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Thread: Does PDF.JS render acccessible PDF experience?
Number of posts in this thread: 14 (In chronological order)
From: Birkir R. Gunnarsson
Date: Tue, Jun 18 2024 5:51AM
Subject: Does PDF.JS render acccessible PDF experience?
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I'm working with a group that is considering using this solution for PDF
files:
https://github.com/mozilla/pdf.js#online-demo
I'm curious if anyone has ever worked with it, i.e. fed it an accessible
(fully tagged) PDF file and verified that it renders an accessible screen
reader user experience.
I've seen a couple of examples that look less than accessible but I found
those in the wil and have not verified the PDF files themselves.
Ultimately I'll have to build this and try it out, but if someone already
has experience with it, I always appreciate knowing what to expect. ;)
Thanks
-Birkir
--
Work hard. Have fun. Make history.
From: Jon Metz
Date: Tue, Jun 18 2024 11:09AM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
Hi Birkir!
PDF.js parses a PDF using the HTML5 Canvas element. It does not look at the tag structure of the PDF (probably for security purposes). I believe that if you also download the PDF from the browser, it is the same as 'printing' it from the browser, so it's not the same file that was properly tagged.
Here's an article that goes into better detail about how pdf.js works:
https://pdfjs.express/blog/how-pdf-js-works
HTH!
Jon Metz
-----Original Message-----
From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Birkir R. Gunnarsson
Sent: Tuesday, June 18, 2024 7:51 AM
To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
I'm working with a group that is considering using this solution for PDF
files:
https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*online-demo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
I'm curious if anyone has ever worked with it, i.e. fed it an accessible (fully tagged) PDF file and verified that it renders an accessible screen reader user experience.
I've seen a couple of examples that look less than accessible but I found those in the wil and have not verified the PDF files themselves.
Ultimately I'll have to build this and try it out, but if someone already has experience with it, I always appreciate knowing what to expect. ;) Thanks -Birkir
--
Work hard. Have fun. Make history.
The information contained in this email message and any attachments is confidential and intended only for the addressee(s). If you are not an addressee, you may not copy or disclose the information, or act upon it, and you should delete it entirely from your email system. Please notify the sender that you received this email in error.
From: Duff Johnson
Date: Tue, Jun 18 2024 11:18AM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
> On Jun 18, 2024, at 13:09, Jon Metz < = EMAIL ADDRESS REMOVED = > wrote:
>
> Hi Birkir!
>
> PDF.js parses a PDF using the HTML5 Canvas element. It does not look at the tag structure of the PDF (probably for security purposes).
Thatâs interesting; Iâm not aware of any security reason to ignore PDF tags.
If itâs true that PDF.js ignores tags then, ipso facto, PDF.js cannot be used where accessibility is required.
Duff.
>
> -----Original Message-----
> From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Birkir R. Gunnarsson
> Sent: Tuesday, June 18, 2024 7:51 AM
> To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>
> I'm working with a group that is considering using this solution for PDF
> files:
> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*online-demo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>
>
> I'm curious if anyone has ever worked with it, i.e. fed it an accessible (fully tagged) PDF file and verified that it renders an accessible screen reader user experience.
> I've seen a couple of examples that look less than accessible but I found those in the wil and have not verified the PDF files themselves.
> Ultimately I'll have to build this and try it out, but if someone already has experience with it, I always appreciate knowing what to expect. ;) Thanks -Birkir
> --
> Work hard. Have fun. Make history.
> > > > >
> The information contained in this email message and any attachments is confidential and intended only for the addressee(s). If you are not an addressee, you may not copy or disclose the information, or act upon it, and you should delete it entirely from your email system. Please notify the sender that you received this email in error.
> > > >
From: Jon Metz
Date: Tue, Jun 18 2024 12:10PM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
Well, I don't know if it's for security reasons. I just assumed "security" was why Adobe limits access to the structure in their Reader app. Or any useful 3rd party plug in for that matter.
But you'd probably know better than I would! :)
-Jon
-----Original Message-----
From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Duff Johnson
Sent: Tuesday, June 18, 2024 1:18 PM
To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
> On Jun 18, 2024, at 13:09, Jon Metz < = EMAIL ADDRESS REMOVED = > wrote:
>
> Hi Birkir!
>
> PDF.js parses a PDF using the HTML5 Canvas element. It does not look at the tag structure of the PDF (probably for security purposes).
Thatâs interesting; Iâm not aware of any security reason to ignore PDF tags.
If itâs true that PDF.js ignores tags then, ipso facto, PDF.js cannot be used where accessibility is required.
Duff.
>
> -----Original Message-----
> From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of
> Birkir R. Gunnarsson
> Sent: Tuesday, June 18, 2024 7:51 AM
> To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>
> I'm working with a group that is considering using this solution for
> PDF
> files:
> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*online-d
> emo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL
> 1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>
>
> I'm curious if anyone has ever worked with it, i.e. fed it an accessible (fully tagged) PDF file and verified that it renders an accessible screen reader user experience.
> I've seen a couple of examples that look less than accessible but I found those in the wil and have not verified the PDF files themselves.
> Ultimately I'll have to build this and try it out, but if someone
> already has experience with it, I always appreciate knowing what to
> expect. ;) Thanks -Birkir
> --
> Work hard. Have fun. Make history.
> > > https://urldefense.com/v3/__http://list.webaim.org/__;!!A7EtB5C7gltH1x
> vgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL1x6gUC7mzzY6o5Niy1T1Ywor
> pQi3qJ5fxhSejRWQ9c0casDC3JSB$ List archives at
> https://urldefense.com/v3/__http://webaim.org/discussion/archives__;!!
> A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL1x6gUC7mzz
> Y6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0calj0XOck$
> >
> The information contained in this email message and any attachments is confidential and intended only for the addressee(s). If you are not an addressee, you may not copy or disclose the information, or act upon it, and you should delete it entirely from your email system. Please notify the sender that you received this email in error.
> > > https://urldefense.com/v3/__http://list.webaim.org/__;!!A7EtB5C7gltH1x
> vgflR8MP4!FiTDhLGB_m8GiFuJRAkkfC5AaMiMMbYyhiUYM_-csZaa2cUae8GvBjnEFc5a
> 2bLKmm5y5Du9oT2ltCoC7n4$ List archives at
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> Uae8GvBjnEFc5a2bLKmm5y5Du9oT2lUMJozD4$
>
From: Duff Johnson
Date: Tue, Jun 18 2024 12:27PM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
> On Jun 18, 2024, at 14:10, Jon Metz < = EMAIL ADDRESS REMOVED = > wrote:
>
> Well, I don't know if it's for security reasons. I just assumed "security" was why Adobe limits access to the structure in their Reader app.
So far as I know Adobe doesnât limit access to the structure in any wayâ¦
Duff.
>
> -----Original Message-----
> From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Duff Johnson
> Sent: Tuesday, June 18, 2024 1:18 PM
> To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>
>
>> On Jun 18, 2024, at 13:09, Jon Metz < = EMAIL ADDRESS REMOVED = > wrote:
>>
>> Hi Birkir!
>>
>> PDF.js parses a PDF using the HTML5 Canvas element. It does not look at the tag structure of the PDF (probably for security purposes).
>
> Thatâs interesting; Iâm not aware of any security reason to ignore PDF tags.
>
> If itâs true that PDF.js ignores tags then, ipso facto, PDF.js cannot be used where accessibility is required.
>
> Duff.
>
>>
>> -----Original Message-----
>> From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of
>> Birkir R. Gunnarsson
>> Sent: Tuesday, June 18, 2024 7:51 AM
>> To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
>> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>
>> I'm working with a group that is considering using this solution for
>> PDF
>> files:
>> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*online-d
>> emo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL
>> 1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>>
>>
>> I'm curious if anyone has ever worked with it, i.e. fed it an accessible (fully tagged) PDF file and verified that it renders an accessible screen reader user experience.
>> I've seen a couple of examples that look less than accessible but I found those in the wil and have not verified the PDF files themselves.
>> Ultimately I'll have to build this and try it out, but if someone
>> already has experience with it, I always appreciate knowing what to
>> expect. ;) Thanks -Birkir
>> --
>> Work hard. Have fun. Make history.
>> >> >> https://urldefense.com/v3/__http://list.webaim.org/__;!!A7EtB5C7gltH1x
>> vgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL1x6gUC7mzzY6o5Niy1T1Ywor
>> pQi3qJ5fxhSejRWQ9c0casDC3JSB$ List archives at
>> https://urldefense.com/v3/__http://webaim.org/discussion/archives__;!!
>> A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL1x6gUC7mzz
>> Y6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0calj0XOck$
>> >>
>> The information contained in this email message and any attachments is confidential and intended only for the addressee(s). If you are not an addressee, you may not copy or disclose the information, or act upon it, and you should delete it entirely from your email system. Please notify the sender that you received this email in error.
>> >> >> https://urldefense.com/v3/__http://list.webaim.org/__;!!A7EtB5C7gltH1x
>> vgflR8MP4!FiTDhLGB_m8GiFuJRAkkfC5AaMiMMbYyhiUYM_-csZaa2cUae8GvBjnEFc5a
>> 2bLKmm5y5Du9oT2ltCoC7n4$ List archives at
>> https://urldefense.com/v3/__http://webaim.org/discussion/archives__;!!
>> A7EtB5C7gltH1xvgflR8MP4!FiTDhLGB_m8GiFuJRAkkfC5AaMiMMbYyhiUYM_-csZaa2c
>> Uae8GvBjnEFc5a2bLKmm5y5Du9oT2lUMJozD4$
>> >
> > > > > > > >
From: Malthe Jepsen
Date: Wed, Jun 19 2024 3:15AM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
HI
According to this Bugzilla page, pdf.js does indeed support tagged PDF. Itâs the default viewer in Firefox, and after a cursory inspection of a tagged PDF in Firefox with a screen reader, it seems to render well.
https://bugzilla.mozilla.org/show_bug.cgi?id1157
Best
Malthe
> On 18 Jun 2024, at 20.27, Duff Johnson < = EMAIL ADDRESS REMOVED = > wrote:
>
>
>> On Jun 18, 2024, at 14:10, Jon Metz < = EMAIL ADDRESS REMOVED = > wrote:
>>
>> Well, I don't know if it's for security reasons. I just assumed "security" was why Adobe limits access to the structure in their Reader app.
>
> So far as I know Adobe doesnât limit access to the structure in any wayâ¦
>
> Duff.
>
>>
>> -----Original Message-----
>> From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Duff Johnson
>> Sent: Tuesday, June 18, 2024 1:18 PM
>> To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
>> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>
>>
>>> On Jun 18, 2024, at 13:09, Jon Metz < = EMAIL ADDRESS REMOVED = > wrote:
>>>
>>> Hi Birkir!
>>>
>>> PDF.js parses a PDF using the HTML5 Canvas element. It does not look at the tag structure of the PDF (probably for security purposes).
>>
>> Thatâs interesting; Iâm not aware of any security reason to ignore PDF tags.
>>
>> If itâs true that PDF.js ignores tags then, ipso facto, PDF.js cannot be used where accessibility is required.
>>
>> Duff.
>>
>>>
>>> -----Original Message-----
>>> From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of
>>> Birkir R. Gunnarsson
>>> Sent: Tuesday, June 18, 2024 7:51 AM
>>> To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
>>> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>
>>> I'm working with a group that is considering using this solution for
>>> PDF
>>> files:
>>> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*online-d
>>> emo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL
>>> 1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>>>
>>>
>>> I'm curious if anyone has ever worked with it, i.e. fed it an accessible (fully tagged) PDF file and verified that it renders an accessible screen reader user experience.
>>> I've seen a couple of examples that look less than accessible but I found those in the wil and have not verified the PDF files themselves.
>>> Ultimately I'll have to build this and try it out, but if someone
>>> already has experience with it, I always appreciate knowing what to
>>> expect. ;) Thanks -Birkir
>>> --
>>> Work hard. Have fun. Make history.
>>> >>> >>> https://urldefense.com/v3/__http://list.webaim.org/__;!!A7EtB5C7gltH1x
>>> vgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL1x6gUC7mzzY6o5Niy1T1Ywor
>>> pQi3qJ5fxhSejRWQ9c0casDC3JSB$ List archives at
>>> https://urldefense.com/v3/__http://webaim.org/discussion/archives__;!!
>>> A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL1x6gUC7mzz
>>> Y6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0calj0XOck$
>>> >>>
>>> The information contained in this email message and any attachments is confidential and intended only for the addressee(s). If you are not an addressee, you may not copy or disclose the information, or act upon it, and you should delete it entirely from your email system. Please notify the sender that you received this email in error.
>>> >>> >>> https://urldefense.com/v3/__http://list.webaim.org/__;!!A7EtB5C7gltH1x
>>> vgflR8MP4!FiTDhLGB_m8GiFuJRAkkfC5AaMiMMbYyhiUYM_-csZaa2cUae8GvBjnEFc5a
>>> 2bLKmm5y5Du9oT2ltCoC7n4$ List archives at
>>> https://urldefense.com/v3/__http://webaim.org/discussion/archives__;!!
>>> A7EtB5C7gltH1xvgflR8MP4!FiTDhLGB_m8GiFuJRAkkfC5AaMiMMbYyhiUYM_-csZaa2c
>>> Uae8GvBjnEFc5a2bLKmm5y5Du9oT2lUMJozD4$
>>> >>
>> >> >> >> >> >> >> >> >
> > > >
From: Philip Kiff
Date: Wed, Jun 19 2024 7:56AM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
I think Malthe is right that pdf.js generally tries to support tagged PDF.
My understanding is that the Mozilla team have been actively working on
improving that support over the past year or two. For example, I know
that last year they worked on trying to maintain the tag order and
structures after you "edit" (more properly annotate) a PDF through the
Firefox browser. And their current issue queue includes a variety of
issues that relate to proper rendering of PDF features required for
accessible PDFs - for example, proper processing of merged table header
cells in tables with more than one row header
(https://github.com/mozilla/pdf.js/issues/18090).
The level of tag support in pdf.js is an active, moving target. But my
impression is that folks who use screen readers still usually prefer to
open PDFs in external PDF reader software?
It would be interesting to see someone do a full comparison of the level
of accessibility support provided by Firefox vs Chrome vs Acrobat.
Phil.
Philip Kiff
D4K Communications
On 2024-06-19 5:15 a.m., Malthe Jepsen wrote:
> HI
> According to this Bugzilla page, pdf.js does indeed support tagged PDF. Itâs the default viewer in Firefox, and after a cursory inspection of a tagged PDF in Firefox with a screen reader, it seems to render well.
> https://bugzilla.mozilla.org/show_bug.cgi?id1157
>
> Best
> Malthe
>> On 18 Jun 2024, at 20.27, Duff Johnson< = EMAIL ADDRESS REMOVED = > wrote:
>>
>>
>>> On Jun 18, 2024, at 14:10, Jon Metz< = EMAIL ADDRESS REMOVED = > wrote:
>>>
>>> Well, I don't know if it's for security reasons. I just assumed "security" was why Adobe limits access to the structure in their Reader app.
>> So far as I know Adobe doesnât limit access to the structure in any wayâ¦
>>
>> Duff.
>>
>>> -----Original Message-----
>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = > On Behalf Of Duff Johnson
>>> Sent: Tuesday, June 18, 2024 1:18 PM
>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = >
>>> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>
>>>
>>>> On Jun 18, 2024, at 13:09, Jon Metz< = EMAIL ADDRESS REMOVED = > wrote:
>>>>
>>>> Hi Birkir!
>>>>
>>>> PDF.js parses a PDF using the HTML5 Canvas element. It does not look at the tag structure of the PDF (probably for security purposes).
>>> Thatâs interesting; Iâm not aware of any security reason to ignore PDF tags.
>>>
>>> If itâs true that PDF.js ignores tags then, ipso facto, PDF.js cannot be used where accessibility is required.
>>>
>>> Duff.
>>>
>>>> -----Original Message-----
>>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = > On Behalf Of
>>>> Birkir R. Gunnarsson
>>>> Sent: Tuesday, June 18, 2024 7:51 AM
>>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = >
>>>> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>>
>>>> I'm working with a group that is considering using this solution for
>>>> PDF
>>>> files:
>>>> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*online-d
>>>> emo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL
>>>> 1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>>>>
>>>>
>>>> I'm curious if anyone has ever worked with it, i.e. fed it an accessible (fully tagged) PDF file and verified that it renders an accessible screen reader user experience.
>>>> I've seen a couple of examples that look less than accessible but I found those in the wil and have not verified the PDF files themselves.
>>>> Ultimately I'll have to build this and try it out, but if someone
>>>> already has experience with it, I always appreciate knowing what to
>>>> expect. ;) Thanks -Birkir
>>>> --
>>>> Work hard. Have fun. Make history.
>>>> >>>>
From: Steve Green
Date: Wed, Jun 19 2024 8:30AM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
It's funny you should mention editing PDFs in Firefox, because Mozilla sent out an email this morning with the subject line "All you need to edit your PDFs". It talks about how you can use Firefox to add text and "you can add images with alt text for accessibility".
I upgraded to the latest version of Firefox and tried it, and it's nothing short of disastrous. The fact that the "Try it now" and "Read more" buttons in the email don't work makes me wonder if it's a draft that they sent out by accident.
I edited a PDF we had already made accessible and found the following:
⢠Editing in Firefox removed all the tags.
⢠It added all the new content in the Comments panel.
⢠You canât set the size of a text frame and the text doesnât wrap, so it flows off screen as you type. However, when you save the document, the text frame gets moved to the extreme left and the font size gets reduced to (almost) fit the page width.
⢠When you add an image, you are prompted to add Alternate Text. However, as far as I can tell, you never see it again â itâs not in the Properties or anywhere else. NVDA canât even find any images in the document.
That said, Firefox is by far the best browser for reading PDFs with a screen reader because it recognises all the tags (as far as I can tell). By contrast, Chrome and Edge are terrible. They ignore the Tags panel and do not expose any semantics at all. They guess what the headings are, apparently based on font size, but every heading is level 2.
I am on an email forum for screen reader users, and there is absolutely no awareness of the level of accessibility support provided by different PDF readers. The topic comes up pretty much every week, and itâs clear that people just use whatever the default reader turns out to be, and itâs almost always a browser because they do everything they can to hijack the PDF file association. Almost no one makes a conscious choice to use a particular application. Worse still, there are all sorts of old wivesâ tales about which reader application is best, almost all of which are wrong.
Steve Green
Managing Director
Test Partners Ltd
-----Original Message-----
From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Philip Kiff
Sent: Wednesday, June 19, 2024 2:57 PM
To: = EMAIL ADDRESS REMOVED =
Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
I think Malthe is right that pdf.js generally tries to support tagged PDF.
My understanding is that the Mozilla team have been actively working on improving that support over the past year or two. For example, I know that last year they worked on trying to maintain the tag order and structures after you "edit" (more properly annotate) a PDF through the Firefox browser. And their current issue queue includes a variety of issues that relate to proper rendering of PDF features required for accessible PDFs - for example, proper processing of merged table header cells in tables with more than one row header (https://github.com/mozilla/pdf.js/issues/18090).
The level of tag support in pdf.js is an active, moving target. But my impression is that folks who use screen readers still usually prefer to open PDFs in external PDF reader software?
It would be interesting to see someone do a full comparison of the level of accessibility support provided by Firefox vs Chrome vs Acrobat.
Phil.
Philip Kiff
D4K Communications
On 2024-06-19 5:15 a.m., Malthe Jepsen wrote:
> HI
> According to this Bugzilla page, pdf.js does indeed support tagged PDF. Itâs the default viewer in Firefox, and after a cursory inspection of a tagged PDF in Firefox with a screen reader, it seems to render well.
> https://bugzilla.mozilla.org/show_bug.cgi?id1157
>
> Best
> Malthe
>> On 18 Jun 2024, at 20.27, Duff Johnson< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>>
>>
>>> On Jun 18, 2024, at 14:10, Jon Metz< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>>>
>>> Well, I don't know if it's for security reasons. I just assumed "security" was why Adobe limits access to the structure in their Reader app.
>> So far as I know Adobe doesnât limit access to the structure in any
>> wayâ¦
>>
>> Duff.
>>
>>> -----Original Message-----
>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> On Behalf
>>> Of Duff Johnson
>>> Sent: Tuesday, June 18, 2024 1:18 PM
>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >>
>>> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>
>>>
>>>> On Jun 18, 2024, at 13:09, Jon Metz< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>>>>
>>>> Hi Birkir!
>>>>
>>>> PDF.js parses a PDF using the HTML5 Canvas element. It does not look at the tag structure of the PDF (probably for security purposes).
>>> Thatâs interesting; Iâm not aware of any security reason to ignore PDF tags.
>>>
>>> If itâs true that PDF.js ignores tags then, ipso facto, PDF.js cannot be used where accessibility is required.
>>>
>>> Duff.
>>>
>>>> -----Original Message-----
>>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> On Behalf
>>>> Of Birkir R. Gunnarsson
>>>> Sent: Tuesday, June 18, 2024 7:51 AM
>>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >>
>>>> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>>
>>>> I'm working with a group that is considering using this solution
>>>> for PDF
>>>> files:
>>>> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*onlin<https://urldefense.com/v3/__https:/github.com/mozilla/pdf.js*onlin>
>>>> e-d
>>>> emo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJn
>>>> kFL 1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>>>>
>>>>
>>>> I'm curious if anyone has ever worked with it, i.e. fed it an accessible (fully tagged) PDF file and verified that it renders an accessible screen reader user experience.
>>>> I've seen a couple of examples that look less than accessible but I found those in the wil and have not verified the PDF files themselves.
>>>> Ultimately I'll have to build this and try it out, but if someone
>>>> already has experience with it, I always appreciate knowing what to
>>>> expect. ;) Thanks -Birkir
>>>> --
>>>> Work hard. Have fun. Make history.
>>>>
>>>>
From: Nick Bromley
Date: Wed, Jun 19 2024 8:58AM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
Hi Steve,
I'm interested in the forum for screen reader users you mentioned - is this a closed group/by invite only, or is there any joining info you could share?
Kind regards,
Nick
----
Director & Accessibility Consultant
Red Kite Digital Accessibility Ltd
-----Original Message-----
From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Steve Green
Sent: Wednesday, June 19, 2024 3:31 PM
To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
It's funny you should mention editing PDFs in Firefox, because Mozilla sent out an email this morning with the subject line "All you need to edit your PDFs". It talks about how you can use Firefox to add text and "you can add images with alt text for accessibility".
I upgraded to the latest version of Firefox and tried it, and it's nothing short of disastrous. The fact that the "Try it now" and "Read more" buttons in the email don't work makes me wonder if it's a draft that they sent out by accident.
I edited a PDF we had already made accessible and found the following:
⢠Editing in Firefox removed all the tags.
⢠It added all the new content in the Comments panel.
⢠You canât set the size of a text frame and the text doesnât wrap, so it flows off screen as you type. However, when you save the document, the text frame gets moved to the extreme left and the font size gets reduced to (almost) fit the page width.
⢠When you add an image, you are prompted to add Alternate Text. However, as far as I can tell, you never see it again â itâs not in the Properties or anywhere else. NVDA canât even find any images in the document.
That said, Firefox is by far the best browser for reading PDFs with a screen reader because it recognises all the tags (as far as I can tell). By contrast, Chrome and Edge are terrible. They ignore the Tags panel and do not expose any semantics at all. They guess what the headings are, apparently based on font size, but every heading is level 2.
I am on an email forum for screen reader users, and there is absolutely no awareness of the level of accessibility support provided by different PDF readers. The topic comes up pretty much every week, and itâs clear that people just use whatever the default reader turns out to be, and itâs almost always a browser because they do everything they can to hijack the PDF file association. Almost no one makes a conscious choice to use a particular application. Worse still, there are all sorts of old wivesâ tales about which reader application is best, almost all of which are wrong.
Steve Green
Managing Director
Test Partners Ltd
-----Original Message-----
From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Philip Kiff
Sent: Wednesday, June 19, 2024 2:57 PM
To: = EMAIL ADDRESS REMOVED =
Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
I think Malthe is right that pdf.js generally tries to support tagged PDF.
My understanding is that the Mozilla team have been actively working on improving that support over the past year or two. For example, I know that last year they worked on trying to maintain the tag order and structures after you "edit" (more properly annotate) a PDF through the Firefox browser. And their current issue queue includes a variety of issues that relate to proper rendering of PDF features required for accessible PDFs - for example, proper processing of merged table header cells in tables with more than one row header (https://github.com/mozilla/pdf.js/issues/18090).
The level of tag support in pdf.js is an active, moving target. But my impression is that folks who use screen readers still usually prefer to open PDFs in external PDF reader software?
It would be interesting to see someone do a full comparison of the level of accessibility support provided by Firefox vs Chrome vs Acrobat.
Phil.
Philip Kiff
D4K Communications
On 2024-06-19 5:15 a.m., Malthe Jepsen wrote:
> HI
> According to this Bugzilla page, pdf.js does indeed support tagged PDF. Itâs the default viewer in Firefox, and after a cursory inspection of a tagged PDF in Firefox with a screen reader, it seems to render well.
> https://bugzilla.mozilla.org/show_bug.cgi?id1157
>
> Best
> Malthe
>> On 18 Jun 2024, at 20.27, Duff Johnson< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>>
>>
>>> On Jun 18, 2024, at 14:10, Jon Metz< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>>>
>>> Well, I don't know if it's for security reasons. I just assumed "security" was why Adobe limits access to the structure in their Reader app.
>> So far as I know Adobe doesnât limit access to the structure in any
>> wayâ¦
>>
>> Duff.
>>
>>> -----Original Message-----
>>> From:
>>> WebAIM-Forum< = EMAIL ADDRESS REMOVED = <mailto:webaim-foru
>>> = EMAIL ADDRESS REMOVED = >> On Behalf
>>> Of Duff Johnson
>>> Sent: Tuesday, June 18, 2024 1:18 PM
>>> To: WebAIM Discussion
>>> List< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED =
>>> g>>
>>> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>
>>>
>>>> On Jun 18, 2024, at 13:09, Jon Metz< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>>>>
>>>> Hi Birkir!
>>>>
>>>> PDF.js parses a PDF using the HTML5 Canvas element. It does not look at the tag structure of the PDF (probably for security purposes).
>>> Thatâs interesting; Iâm not aware of any security reason to ignore PDF tags.
>>>
>>> If itâs true that PDF.js ignores tags then, ipso facto, PDF.js cannot be used where accessibility is required.
>>>
>>> Duff.
>>>
>>>> -----Original Message-----
>>>> From:
>>>> WebAIM-Forum< = EMAIL ADDRESS REMOVED = <mailto:webaim-for
>>>> = EMAIL ADDRESS REMOVED = >> On Behalf
>>>> Of Birkir R. Gunnarsson
>>>> Sent: Tuesday, June 18, 2024 7:51 AM
>>>> To: WebAIM Discussion
>>>> List< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = .o
>>>> rg>>
>>>> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>>
>>>> I'm working with a group that is considering using this solution
>>>> for PDF
>>>> files:
>>>> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*onlin
>>>> <https://urldefense.com/v3/__https:/github.com/mozilla/pdf.js*onlin
>>>> >
>>>> e-d
>>>> emo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJn
>>>> kFL 1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>>>>
>>>>
>>>> I'm curious if anyone has ever worked with it, i.e. fed it an accessible (fully tagged) PDF file and verified that it renders an accessible screen reader user experience.
>>>> I've seen a couple of examples that look less than accessible but I found those in the wil and have not verified the PDF files themselves.
>>>> Ultimately I'll have to build this and try it out, but if someone
>>>> already has experience with it, I always appreciate knowing what to
>>>> expect. ;) Thanks -Birkir
>>>> --
>>>> Work hard. Have fun. Make history.
>>>> >>>>
From: Philip Kiff
Date: Wed, Jun 19 2024 9:09AM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
Ha! Your mileage definitely will vary if you try to "edit" a PDF using
Firefox!
I wish Mozilla wouldn't even use the word "edit" in their marketing
materials since it's not really an editor. You're not really editing the
PDF file, so much as adding annotations on top of it, which is why they
can end up in the comments. Having said that, I tested a version of it a
few months ago and it did allow an image to be added (to the top layer
of the page) and it did allow the alternative text to be passed through
to a screen reader, and it inserted the figure tag at the end of the tag
tree for that page. I'm surprised it works at all, given the complexity
of the PDF file structure, and I'm interested to see how/if it continues
to develop.
Thanks for the additional insight into screen reader experience and
awareness. The tendency of browsers to take over PDF rendering has been
frustrating for all users, I think, and it has created new challenges to
achieving an accessible PDF experience. So many different rendering
experiences and different tag and form support.
Phil.
On 2024-06-19 10:30 a.m., Steve Green wrote:
> It's funny you should mention editing PDFs in Firefox, because Mozilla sent out an email this morning with the subject line "All you need to edit your PDFs". It talks about how you can use Firefox to add text and "you can add images with alt text for accessibility".
>
> I upgraded to the latest version of Firefox and tried it, and it's nothing short of disastrous. The fact that the "Try it now" and "Read more" buttons in the email don't work makes me wonder if it's a draft that they sent out by accident.
>
> I edited a PDF we had already made accessible and found the following:
>
> ⢠Editing in Firefox removed all the tags.
> ⢠It added all the new content in the Comments panel.
> ⢠You canât set the size of a text frame and the text doesnât wrap, so it flows off screen as you type. However, when you save the document, the text frame gets moved to the extreme left and the font size gets reduced to (almost) fit the page width.
> ⢠When you add an image, you are prompted to add Alternate Text. However, as far as I can tell, you never see it again â itâs not in the Properties or anywhere else. NVDA canât even find any images in the document.
>
> That said, Firefox is by far the best browser for reading PDFs with a screen reader because it recognises all the tags (as far as I can tell). By contrast, Chrome and Edge are terrible. They ignore the Tags panel and do not expose any semantics at all. They guess what the headings are, apparently based on font size, but every heading is level 2.
>
> I am on an email forum for screen reader users, and there is absolutely no awareness of the level of accessibility support provided by different PDF readers. The topic comes up pretty much every week, and itâs clear that people just use whatever the default reader turns out to be, and itâs almost always a browser because they do everything they can to hijack the PDF file association. Almost no one makes a conscious choice to use a particular application. Worse still, there are all sorts of old wivesâ tales about which reader application is best, almost all of which are wrong.
>
> Steve Green
> Managing Director
> Test Partners Ltd
On 2024-06-19 9:56 a.m., Philip Kiff wrote:
> I think Malthe is right that pdf.js generally tries to support tagged
> PDF.
>
> My understanding is that the Mozilla team have been actively working
> on improving that support over the past year or two. For example, I
> know that last year they worked on trying to maintain the tag order
> and structures after you "edit" (more properly annotate) a PDF through
> the Firefox browser. And their current issue queue includes a variety
> of issues that relate to proper rendering of PDF features required for
> accessible PDFs - for example, proper processing of merged table
> header cells in tables with more than one row header
> (https://github.com/mozilla/pdf.js/issues/18090).
>
> The level of tag support in pdf.js is an active, moving target. But my
> impression is that folks who use screen readers still usually prefer
> to open PDFs in external PDF reader software?
>
> It would be interesting to see someone do a full comparison of the
> level of accessibility support provided by Firefox vs Chrome vs Acrobat.
>
> Phil.
>
> Philip Kiff
> D4K Communications
>
> On 2024-06-19 5:15 a.m., Malthe Jepsen wrote:
>> HI
>> According to this Bugzilla page, pdf.js does indeed support tagged
>> PDF. Itâs the default viewer in Firefox, and after a cursory
>> inspection of a tagged PDF in Firefox with a screen reader, it seems
>> to render well.
>> https://bugzilla.mozilla.org/show_bug.cgi?id1157
>>
>> Best
>> Malthe
>>> On 18 Jun 2024, at 20.27, Duff Johnson< = EMAIL ADDRESS REMOVED = >Â wrote:
>>>
>>>
>>>> On Jun 18, 2024, at 14:10, Jon Metz< = EMAIL ADDRESS REMOVED = >Â wrote:
>>>>
>>>> Well, I don't know if it's for security reasons. I just assumed
>>>> "security" was why Adobe limits access to the structure in their
>>>> Reader app.
>>> So far as I know Adobe doesnât limit access to the structure in any
>>> wayâ¦
>>>
>>> Duff.
>>>
>>>> -----Original Message-----
>>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = >Â On Behalf
>>>> Of Duff Johnson
>>>> Sent: Tuesday, June 18, 2024 1:18 PM
>>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = >
>>>> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>>
>>>>
>>>>> On Jun 18, 2024, at 13:09, Jon Metz< = EMAIL ADDRESS REMOVED = >Â wrote:
>>>>>
>>>>> Hi Birkir!
>>>>>
>>>>> PDF.js parses a PDF using the HTML5 Canvas element. It does not
>>>>> look at the tag structure of the PDF (probably for security
>>>>> purposes).
>>>> Thatâs interesting; Iâm not aware of any security reason to ignore
>>>> PDF tags.
>>>>
>>>> If itâs true that PDF.js ignores tags then, ipso facto, PDF.js
>>>> cannot be used where accessibility is required.
>>>>
>>>> Duff.
>>>>
>>>>> -----Original Message-----
>>>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = > On Behalf Of
>>>>> Birkir R. Gunnarsson
>>>>> Sent: Tuesday, June 18, 2024 7:51 AM
>>>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = >
>>>>> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>>>
>>>>> I'm working with a group that is considering using this solution for
>>>>> PDF
>>>>> files:
>>>>> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*online-d
>>>>>
>>>>> emo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJnkFL
>>>>>
>>>>> 1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>>>>>
>>>>>
>>>>> I'm curious if anyone has ever worked with it, i.e. fed it an
>>>>> accessible (fully tagged) PDF file and verified that it renders an
>>>>> accessible screen reader user experience.
>>>>> I've seen a couple of examples that look less than accessible but
>>>>> I found those in the wil and have not verified the PDF files
>>>>> themselves.
>>>>> Ultimately I'll have to build this and try it out, but if someone
>>>>> already has experience with it, I always appreciate knowing what to
>>>>> expect. ;) Thanks -Birkir
>>>>> --
>>>>> Work hard. Have fun. Make history.
>>>>> >>>>>
> > > >
From: Steve Green
Date: Wed, Jun 19 2024 9:25AM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
Hi Nick,
I just replied to you off-list.
Steve
-----Original Message-----
From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Nick Bromley
Sent: Wednesday, June 19, 2024 3:59 PM
To: 'WebAIM Discussion List' < = EMAIL ADDRESS REMOVED = >
Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
Hi Steve,
I'm interested in the forum for screen reader users you mentioned - is this a closed group/by invite only, or is there any joining info you could share?
Kind regards,
Nick
----
Director & Accessibility Consultant
Red Kite Digital Accessibility Ltd
-----Original Message-----
From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Steve Green
Sent: Wednesday, June 19, 2024 3:31 PM
To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
It's funny you should mention editing PDFs in Firefox, because Mozilla sent out an email this morning with the subject line "All you need to edit your PDFs". It talks about how you can use Firefox to add text and "you can add images with alt text for accessibility".
I upgraded to the latest version of Firefox and tried it, and it's nothing short of disastrous. The fact that the "Try it now" and "Read more" buttons in the email don't work makes me wonder if it's a draft that they sent out by accident.
I edited a PDF we had already made accessible and found the following:
⢠Editing in Firefox removed all the tags.
⢠It added all the new content in the Comments panel.
⢠You canât set the size of a text frame and the text doesnât wrap, so it flows off screen as you type. However, when you save the document, the text frame gets moved to the extreme left and the font size gets reduced to (almost) fit the page width.
⢠When you add an image, you are prompted to add Alternate Text. However, as far as I can tell, you never see it again â itâs not in the Properties or anywhere else. NVDA canât even find any images in the document.
That said, Firefox is by far the best browser for reading PDFs with a screen reader because it recognises all the tags (as far as I can tell). By contrast, Chrome and Edge are terrible. They ignore the Tags panel and do not expose any semantics at all. They guess what the headings are, apparently based on font size, but every heading is level 2.
I am on an email forum for screen reader users, and there is absolutely no awareness of the level of accessibility support provided by different PDF readers. The topic comes up pretty much every week, and itâs clear that people just use whatever the default reader turns out to be, and itâs almost always a browser because they do everything they can to hijack the PDF file association. Almost no one makes a conscious choice to use a particular application. Worse still, there are all sorts of old wivesâ tales about which reader application is best, almost all of which are wrong.
Steve Green
Managing Director
Test Partners Ltd
-----Original Message-----
From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Philip Kiff
Sent: Wednesday, June 19, 2024 2:57 PM
To: = EMAIL ADDRESS REMOVED =
Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
I think Malthe is right that pdf.js generally tries to support tagged PDF.
My understanding is that the Mozilla team have been actively working on improving that support over the past year or two. For example, I know that last year they worked on trying to maintain the tag order and structures after you "edit" (more properly annotate) a PDF through the Firefox browser. And their current issue queue includes a variety of issues that relate to proper rendering of PDF features required for accessible PDFs - for example, proper processing of merged table header cells in tables with more than one row header (https://github.com/mozilla/pdf.js/issues/18090).
The level of tag support in pdf.js is an active, moving target. But my impression is that folks who use screen readers still usually prefer to open PDFs in external PDF reader software?
It would be interesting to see someone do a full comparison of the level of accessibility support provided by Firefox vs Chrome vs Acrobat.
Phil.
Philip Kiff
D4K Communications
On 2024-06-19 5:15 a.m., Malthe Jepsen wrote:
> HI
> According to this Bugzilla page, pdf.js does indeed support tagged PDF. Itâs the default viewer in Firefox, and after a cursory inspection of a tagged PDF in Firefox with a screen reader, it seems to render well.
> https://bugzilla.mozilla.org/show_bug.cgi?id1157
>
> Best
> Malthe
>> On 18 Jun 2024, at 20.27, Duff Johnson< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>>
>>
>>> On Jun 18, 2024, at 14:10, Jon Metz< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>>>
>>> Well, I don't know if it's for security reasons. I just assumed "security" was why Adobe limits access to the structure in their Reader app.
>> So far as I know Adobe doesnât limit access to the structure in any
>> wayâ¦
>>
>> Duff.
>>
>>> -----Original Message-----
>>> From:
>>> WebAIM-Forum< = EMAIL ADDRESS REMOVED = <mailto:webaim-foru
>>> = EMAIL ADDRESS REMOVED = >> On Behalf
>>> Of Duff Johnson
>>> Sent: Tuesday, June 18, 2024 1:18 PM
>>> To: WebAIM Discussion
>>> List< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED =
>>> g>>
>>> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>
>>>
>>>> On Jun 18, 2024, at 13:09, Jon Metz< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>>>>
>>>> Hi Birkir!
>>>>
>>>> PDF.js parses a PDF using the HTML5 Canvas element. It does not look at the tag structure of the PDF (probably for security purposes).
>>> Thatâs interesting; Iâm not aware of any security reason to ignore PDF tags.
>>>
>>> If itâs true that PDF.js ignores tags then, ipso facto, PDF.js cannot be used where accessibility is required.
>>>
>>> Duff.
>>>
>>>> -----Original Message-----
>>>> From:
>>>> WebAIM-Forum< = EMAIL ADDRESS REMOVED = <mailto:webaim-for
>>>> = EMAIL ADDRESS REMOVED = >> On Behalf
>>>> Of Birkir R. Gunnarsson
>>>> Sent: Tuesday, June 18, 2024 7:51 AM
>>>> To: WebAIM Discussion
>>>> List< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = .o
>>>> rg>>
>>>> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>>
>>>> I'm working with a group that is considering using this solution
>>>> for PDF
>>>> files:
>>>> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*onlin
>>>> <https://urldefense.com/v3/__https:/github.com/mozilla/pdf.js*onlin
>>>> >
>>>> e-d
>>>> emo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJn
>>>> kFL 1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>>>>
>>>>
>>>> I'm curious if anyone has ever worked with it, i.e. fed it an accessible (fully tagged) PDF file and verified that it renders an accessible screen reader user experience.
>>>> I've seen a couple of examples that look less than accessible but I found those in the wil and have not verified the PDF files themselves.
>>>> Ultimately I'll have to build this and try it out, but if someone
>>>> already has experience with it, I always appreciate knowing what to
>>>> expect. ;) Thanks -Birkir
>>>> --
>>>> Work hard. Have fun. Make history.
>>>>
>>>>
From: Steve Green
Date: Wed, Jun 19 2024 9:39AM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
I'd love to know how you managed to add an image with alt text. I was expecting to be able to do that, but I can't find a way to do so. When I autotag the document after adding an image, the image itself is not visible in the Tags or Content panel. Instead, it appears as a Stamp-OBJR inside an <Annot> tag.
Steve
-----Original Message-----
From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Philip Kiff
Sent: Wednesday, June 19, 2024 4:09 PM
To: = EMAIL ADDRESS REMOVED =
Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
Ha! Your mileage definitely will vary if you try to "edit" a PDF using Firefox!
I wish Mozilla wouldn't even use the word "edit" in their marketing materials since it's not really an editor. You're not really editing the PDF file, so much as adding annotations on top of it, which is why they can end up in the comments. Having said that, I tested a version of it a few months ago and it did allow an image to be added (to the top layer of the page) and it did allow the alternative text to be passed through to a screen reader, and it inserted the figure tag at the end of the tag tree for that page. I'm surprised it works at all, given the complexity of the PDF file structure, and I'm interested to see how/if it continues to develop.
Thanks for the additional insight into screen reader experience and awareness. The tendency of browsers to take over PDF rendering has been frustrating for all users, I think, and it has created new challenges to achieving an accessible PDF experience. So many different rendering experiences and different tag and form support.
Phil.
On 2024-06-19 10:30 a.m., Steve Green wrote:
> It's funny you should mention editing PDFs in Firefox, because Mozilla sent out an email this morning with the subject line "All you need to edit your PDFs". It talks about how you can use Firefox to add text and "you can add images with alt text for accessibility".
>
> I upgraded to the latest version of Firefox and tried it, and it's nothing short of disastrous. The fact that the "Try it now" and "Read more" buttons in the email don't work makes me wonder if it's a draft that they sent out by accident.
>
> I edited a PDF we had already made accessible and found the following:
>
> ⢠Editing in Firefox removed all the tags.
> ⢠It added all the new content in the Comments panel.
> ⢠You canât set the size of a text frame and the text doesnât wrap, so it flows off screen as you type. However, when you save the document, the text frame gets moved to the extreme left and the font size gets reduced to (almost) fit the page width.
> ⢠When you add an image, you are prompted to add Alternate Text. However, as far as I can tell, you never see it again â itâs not in the Properties or anywhere else. NVDA canât even find any images in the document.
>
> That said, Firefox is by far the best browser for reading PDFs with a screen reader because it recognises all the tags (as far as I can tell). By contrast, Chrome and Edge are terrible. They ignore the Tags panel and do not expose any semantics at all. They guess what the headings are, apparently based on font size, but every heading is level 2.
>
> I am on an email forum for screen reader users, and there is absolutely no awareness of the level of accessibility support provided by different PDF readers. The topic comes up pretty much every week, and itâs clear that people just use whatever the default reader turns out to be, and itâs almost always a browser because they do everything they can to hijack the PDF file association. Almost no one makes a conscious choice to use a particular application. Worse still, there are all sorts of old wivesâ tales about which reader application is best, almost all of which are wrong.
>
> Steve Green
> Managing Director
> Test Partners Ltd
On 2024-06-19 9:56 a.m., Philip Kiff wrote:
> I think Malthe is right that pdf.js generally tries to support tagged
> PDF.
>
> My understanding is that the Mozilla team have been actively working
> on improving that support over the past year or two. For example, I
> know that last year they worked on trying to maintain the tag order
> and structures after you "edit" (more properly annotate) a PDF through
> the Firefox browser. And their current issue queue includes a variety
> of issues that relate to proper rendering of PDF features required for
> accessible PDFs - for example, proper processing of merged table
> header cells in tables with more than one row header
> (https://github.com/mozilla/pdf.js/issues/18090).
>
> The level of tag support in pdf.js is an active, moving target. But my
> impression is that folks who use screen readers still usually prefer
> to open PDFs in external PDF reader software?
>
> It would be interesting to see someone do a full comparison of the
> level of accessibility support provided by Firefox vs Chrome vs Acrobat.
>
> Phil.
>
> Philip Kiff
> D4K Communications
>
> On 2024-06-19 5:15 a.m., Malthe Jepsen wrote:
>> HI
>> According to this Bugzilla page, pdf.js does indeed support tagged
>> PDF. Itâs the default viewer in Firefox, and after a cursory
>> inspection of a tagged PDF in Firefox with a screen reader, it seems
>> to render well.
>> https://bugzilla.mozilla.org/show_bug.cgi?id1157
>>
>> Best
>> Malthe
>>> On 18 Jun 2024, at 20.27, Duff Johnson< = EMAIL ADDRESS REMOVED = >Â wrote:
>>>
>>>
>>>> On Jun 18, 2024, at 14:10, Jon Metz< = EMAIL ADDRESS REMOVED = >Â wrote:
>>>>
>>>> Well, I don't know if it's for security reasons. I just assumed
>>>> "security" was why Adobe limits access to the structure in their
>>>> Reader app.
>>> So far as I know Adobe doesnât limit access to the structure in any
>>> wayâ¦
>>>
>>> Duff.
>>>
>>>> -----Original Message-----
>>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = >Â On Behalf
>>>> Of Duff Johnson
>>>> Sent: Tuesday, June 18, 2024 1:18 PM
>>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = >
>>>> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>>
>>>>
>>>>> On Jun 18, 2024, at 13:09, Jon Metz< = EMAIL ADDRESS REMOVED = >Â wrote:
>>>>>
>>>>> Hi Birkir!
>>>>>
>>>>> PDF.js parses a PDF using the HTML5 Canvas element. It does not
>>>>> look at the tag structure of the PDF (probably for security
>>>>> purposes).
>>>> Thatâs interesting; Iâm not aware of any security reason to ignore
>>>> PDF tags.
>>>>
>>>> If itâs true that PDF.js ignores tags then, ipso facto, PDF.js
>>>> cannot be used where accessibility is required.
>>>>
>>>> Duff.
>>>>
>>>>> -----Original Message-----
>>>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = > On Behalf
>>>>> Of Birkir R. Gunnarsson
>>>>> Sent: Tuesday, June 18, 2024 7:51 AM
>>>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = >
>>>>> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>>>
>>>>> I'm working with a group that is considering using this solution
>>>>> for PDF
>>>>> files:
>>>>> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*onli
>>>>> ne-d
>>>>>
>>>>> emo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJ
>>>>> nkFL
>>>>>
>>>>> 1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>>>>>
>>>>>
>>>>> I'm curious if anyone has ever worked with it, i.e. fed it an
>>>>> accessible (fully tagged) PDF file and verified that it renders an
>>>>> accessible screen reader user experience.
>>>>> I've seen a couple of examples that look less than accessible but
>>>>> I found those in the wil and have not verified the PDF files
>>>>> themselves.
>>>>> Ultimately I'll have to build this and try it out, but if someone
>>>>> already has experience with it, I always appreciate knowing what
>>>>> to expect. ;) Thanks -Birkir
>>>>> --
>>>>> Work hard. Have fun. Make history.
>>>>> >>>>>
> > > archives at http://webaim.org/discussion/archives
>
From: Duff Johnson
Date: Wed, Jun 19 2024 9:55AM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | Next message →
HI Steve,
Thanks for this great report.
Related: this recent article on pdfa.org by our CTO, Peter Wyatt, provides a comparison of how browsers handle PDFâs Fragment Identifiers feature⦠and their support for basic PDF navigation features in general.
https://pdfa.org/pdf-fragment-identifiers/
Sadly, although all browsers support some Fragment Identifiers none support the ability to target a structure element (tag).
Duff.
> On Jun 19, 2024, at 10:30, Steve Green < = EMAIL ADDRESS REMOVED = > wrote:
>
> It's funny you should mention editing PDFs in Firefox, because Mozilla sent out an email this morning with the subject line "All you need to edit your PDFs". It talks about how you can use Firefox to add text and "you can add images with alt text for accessibility".
>
>
>
> I upgraded to the latest version of Firefox and tried it, and it's nothing short of disastrous. The fact that the "Try it now" and "Read more" buttons in the email don't work makes me wonder if it's a draft that they sent out by accident.
>
>
>
> I edited a PDF we had already made accessible and found the following:
>
>
>
> ⢠Editing in Firefox removed all the tags.
>
>
> ⢠It added all the new content in the Comments panel.
>
>
> ⢠You canât set the size of a text frame and the text doesnât wrap, so it flows off screen as you type. However, when you save the document, the text frame gets moved to the extreme left and the font size gets reduced to (almost) fit the page width.
>
>
> ⢠When you add an image, you are prompted to add Alternate Text. However, as far as I can tell, you never see it again â itâs not in the Properties or anywhere else. NVDA canât even find any images in the document.
>
>
>
> That said, Firefox is by far the best browser for reading PDFs with a screen reader because it recognises all the tags (as far as I can tell). By contrast, Chrome and Edge are terrible. They ignore the Tags panel and do not expose any semantics at all. They guess what the headings are, apparently based on font size, but every heading is level 2.
>
>
>
> I am on an email forum for screen reader users, and there is absolutely no awareness of the level of accessibility support provided by different PDF readers. The topic comes up pretty much every week, and itâs clear that people just use whatever the default reader turns out to be, and itâs almost always a browser because they do everything they can to hijack the PDF file association. Almost no one makes a conscious choice to use a particular application. Worse still, there are all sorts of old wivesâ tales about which reader application is best, almost all of which are wrong.
>
> Steve Green
> Managing Director
> Test Partners Ltd
>
>
>
>
> -----Original Message-----
> From: WebAIM-Forum < = EMAIL ADDRESS REMOVED = > On Behalf Of Philip Kiff
> Sent: Wednesday, June 19, 2024 2:57 PM
> To: = EMAIL ADDRESS REMOVED =
> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>
>
>
> I think Malthe is right that pdf.js generally tries to support tagged PDF.
>
>
>
> My understanding is that the Mozilla team have been actively working on improving that support over the past year or two. For example, I know that last year they worked on trying to maintain the tag order and structures after you "edit" (more properly annotate) a PDF through the Firefox browser. And their current issue queue includes a variety of issues that relate to proper rendering of PDF features required for accessible PDFs - for example, proper processing of merged table header cells in tables with more than one row header (https://github.com/mozilla/pdf.js/issues/18090).
>
>
>
> The level of tag support in pdf.js is an active, moving target. But my impression is that folks who use screen readers still usually prefer to open PDFs in external PDF reader software?
>
>
>
> It would be interesting to see someone do a full comparison of the level of accessibility support provided by Firefox vs Chrome vs Acrobat.
>
>
>
> Phil.
>
>
>
> Philip Kiff
>
> D4K Communications
>
>
>
> On 2024-06-19 5:15 a.m., Malthe Jepsen wrote:
>
>> HI
>
>> According to this Bugzilla page, pdf.js does indeed support tagged PDF. Itâs the default viewer in Firefox, and after a cursory inspection of a tagged PDF in Firefox with a screen reader, it seems to render well.
>
>> https://bugzilla.mozilla.org/show_bug.cgi?id1157
>
>>
>
>> Best
>
>> Malthe
>
>>> On 18 Jun 2024, at 20.27, Duff Johnson< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>
>>>
>
>>>
>
>>>> On Jun 18, 2024, at 14:10, Jon Metz< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>
>>>>
>
>>>> Well, I don't know if it's for security reasons. I just assumed "security" was why Adobe limits access to the structure in their Reader app.
>
>>> So far as I know Adobe doesnât limit access to the structure in any
>
>>> wayâ¦
>
>>>
>
>>> Duff.
>
>>>
>
>>>> -----Original Message-----
>
>>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> On Behalf
>
>>>> Of Duff Johnson
>
>>>> Sent: Tuesday, June 18, 2024 1:18 PM
>
>>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >>
>
>>>> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>
>>>>
>
>>>>
>
>>>>> On Jun 18, 2024, at 13:09, Jon Metz< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> wrote:
>
>>>>>
>
>>>>> Hi Birkir!
>
>>>>>
>
>>>>> PDF.js parses a PDF using the HTML5 Canvas element. It does not look at the tag structure of the PDF (probably for security purposes).
>
>>>> Thatâs interesting; Iâm not aware of any security reason to ignore PDF tags.
>
>>>>
>
>>>> If itâs true that PDF.js ignores tags then, ipso facto, PDF.js cannot be used where accessibility is required.
>
>>>>
>
>>>> Duff.
>
>>>>
>
>>>>> -----Original Message-----
>
>>>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >> On Behalf
>
>>>>> Of Birkir R. Gunnarsson
>
>>>>> Sent: Tuesday, June 18, 2024 7:51 AM
>
>>>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = <mailto: = EMAIL ADDRESS REMOVED = >>
>
>>>>> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>
>>>>>
>
>>>>> I'm working with a group that is considering using this solution
>
>>>>> for PDF
>
>>>>> files:
>
>>>>> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*onlin<https://urldefense.com/v3/__https:/github.com/mozilla/pdf.js*onlin>
>
>>>>> e-d
>
>>>>> emo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJn
>
>>>>> kFL 1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>
>>>>>
>
>>>>>
>
>>>>> I'm curious if anyone has ever worked with it, i.e. fed it an accessible (fully tagged) PDF file and verified that it renders an accessible screen reader user experience.
>
>>>>> I've seen a couple of examples that look less than accessible but I found those in the wil and have not verified the PDF files themselves.
>
>>>>> Ultimately I'll have to build this and try it out, but if someone
>
>>>>> already has experience with it, I always appreciate knowing what to
>
>>>>> expect. ;) Thanks -Birkir
>
>>>>> --
>
>>>>> Work hard. Have fun. Make history.
>
>>>>> >
>>>>>
>
> >
> >
> > > > >
From: Philip Kiff
Date: Wed, Jun 19 2024 11:32AM
Subject: Re: Does PDF.JS render acccessible PDF experience?
← Previous message | No next message
Mmmm....re-testing now, and I don't seem to be able to reproduce what I
said I did. I guess it must have been a personal hallucination (or
misremembering after too many duplicate edits). It looks like you're
right and that none of the Firefox edits get transferred over to the tag
tree or regular content containers: everything remains in annotation.
Which I assume is why the alternative text doesn't appear anywhere,
since there's no provision for it in annotations.
Drats.
Phil.
On 2024-06-19 11:39 a.m., Steve Green wrote:
> I'd love to know how you managed to add an image with alt text. I was expecting to be able to do that, but I can't find a way to do so. When I autotag the document after adding an image, the image itself is not visible in the Tags or Content panel. Instead, it appears as a Stamp-OBJR inside an <Annot> tag.
>
> Steve
>
> -----Original Message-----
> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = > On Behalf Of Philip Kiff
> Sent: Wednesday, June 19, 2024 4:09 PM
> To: = EMAIL ADDRESS REMOVED =
> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>
> Ha! Your mileage definitely will vary if you try to "edit" a PDF using Firefox!
>
> I wish Mozilla wouldn't even use the word "edit" in their marketing materials since it's not really an editor. You're not really editing the PDF file, so much as adding annotations on top of it, which is why they can end up in the comments. Having said that, I tested a version of it a few months ago and it did allow an image to be added (to the top layer of the page) and it did allow the alternative text to be passed through to a screen reader, and it inserted the figure tag at the end of the tag tree for that page. I'm surprised it works at all, given the complexity of the PDF file structure, and I'm interested to see how/if it continues to develop.
>
> Thanks for the additional insight into screen reader experience and awareness. The tendency of browsers to take over PDF rendering has been frustrating for all users, I think, and it has created new challenges to achieving an accessible PDF experience. So many different rendering experiences and different tag and form support.
>
> Phil.
>
> On 2024-06-19 10:30 a.m., Steve Green wrote:
>> It's funny you should mention editing PDFs in Firefox, because Mozilla sent out an email this morning with the subject line "All you need to edit your PDFs". It talks about how you can use Firefox to add text and "you can add images with alt text for accessibility".
>>
>> I upgraded to the latest version of Firefox and tried it, and it's nothing short of disastrous. The fact that the "Try it now" and "Read more" buttons in the email don't work makes me wonder if it's a draft that they sent out by accident.
>>
>> I edited a PDF we had already made accessible and found the following:
>>
>> ⢠Editing in Firefox removed all the tags.
>> ⢠It added all the new content in the Comments panel.
>> ⢠You canât set the size of a text frame and the text doesnât wrap, so it flows off screen as you type. However, when you save the document, the text frame gets moved to the extreme left and the font size gets reduced to (almost) fit the page width.
>> ⢠When you add an image, you are prompted to add Alternate Text. However, as far as I can tell, you never see it again â itâs not in the Properties or anywhere else. NVDA canât even find any images in the document.
>>
>> That said, Firefox is by far the best browser for reading PDFs with a screen reader because it recognises all the tags (as far as I can tell). By contrast, Chrome and Edge are terrible. They ignore the Tags panel and do not expose any semantics at all. They guess what the headings are, apparently based on font size, but every heading is level 2.
>>
>> I am on an email forum for screen reader users, and there is absolutely no awareness of the level of accessibility support provided by different PDF readers. The topic comes up pretty much every week, and itâs clear that people just use whatever the default reader turns out to be, and itâs almost always a browser because they do everything they can to hijack the PDF file association. Almost no one makes a conscious choice to use a particular application. Worse still, there are all sorts of old wivesâ tales about which reader application is best, almost all of which are wrong.
>>
>> Steve Green
>> Managing Director
>> Test Partners Ltd
> On 2024-06-19 9:56 a.m., Philip Kiff wrote:
>> I think Malthe is right that pdf.js generally tries to support tagged
>> PDF.
>>
>> My understanding is that the Mozilla team have been actively working
>> on improving that support over the past year or two. For example, I
>> know that last year they worked on trying to maintain the tag order
>> and structures after you "edit" (more properly annotate) a PDF through
>> the Firefox browser. And their current issue queue includes a variety
>> of issues that relate to proper rendering of PDF features required for
>> accessible PDFs - for example, proper processing of merged table
>> header cells in tables with more than one row header
>> (https://github.com/mozilla/pdf.js/issues/18090).
>>
>> The level of tag support in pdf.js is an active, moving target. But my
>> impression is that folks who use screen readers still usually prefer
>> to open PDFs in external PDF reader software?
>>
>> It would be interesting to see someone do a full comparison of the
>> level of accessibility support provided by Firefox vs Chrome vs Acrobat.
>>
>> Phil.
>>
>> Philip Kiff
>> D4K Communications
>>
>> On 2024-06-19 5:15 a.m., Malthe Jepsen wrote:
>>> HI
>>> According to this Bugzilla page, pdf.js does indeed support tagged
>>> PDF. Itâs the default viewer in Firefox, and after a cursory
>>> inspection of a tagged PDF in Firefox with a screen reader, it seems
>>> to render well.
>>> https://bugzilla.mozilla.org/show_bug.cgi?id1157
>>>
>>> Best
>>> Malthe
>>>> On 18 Jun 2024, at 20.27, Duff Johnson< = EMAIL ADDRESS REMOVED = > Â wrote:
>>>>
>>>>
>>>>> On Jun 18, 2024, at 14:10, Jon Metz< = EMAIL ADDRESS REMOVED = > Â wrote:
>>>>>
>>>>> Well, I don't know if it's for security reasons. I just assumed
>>>>> "security" was why Adobe limits access to the structure in their
>>>>> Reader app.
>>>> So far as I know Adobe doesnât limit access to the structure in any
>>>> wayâ¦
>>>>
>>>> Duff.
>>>>
>>>>> -----Original Message-----
>>>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = > Â On Behalf
>>>>> Of Duff Johnson
>>>>> Sent: Tuesday, June 18, 2024 1:18 PM
>>>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = >
>>>>> Subject: Re: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>>>
>>>>>
>>>>>> On Jun 18, 2024, at 13:09, Jon Metz< = EMAIL ADDRESS REMOVED = > Â wrote:
>>>>>>
>>>>>> Hi Birkir!
>>>>>>
>>>>>> PDF.js parses a PDF using the HTML5 Canvas element. It does not
>>>>>> look at the tag structure of the PDF (probably for security
>>>>>> purposes).
>>>>> Thatâs interesting; Iâm not aware of any security reason to ignore
>>>>> PDF tags.
>>>>>
>>>>> If itâs true that PDF.js ignores tags then, ipso facto, PDF.js
>>>>> cannot be used where accessibility is required.
>>>>>
>>>>> Duff.
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: WebAIM-Forum< = EMAIL ADDRESS REMOVED = > On Behalf
>>>>>> Of Birkir R. Gunnarsson
>>>>>> Sent: Tuesday, June 18, 2024 7:51 AM
>>>>>> To: WebAIM Discussion List< = EMAIL ADDRESS REMOVED = >
>>>>>> Subject: [WebAIM] Does PDF.JS render acccessible PDF experience?
>>>>>>
>>>>>> I'm working with a group that is considering using this solution
>>>>>> for PDF
>>>>>> files:
>>>>>> https://urldefense.com/v3/__https://github.com/mozilla/pdf.js*onli
>>>>>> ne-d
>>>>>>
>>>>>> emo__;Iw!!A7EtB5C7gltH1xvgflR8MP4!GuhdCtxAZUPPA3xodMhCS8qdSf9bAVKJ
>>>>>> nkFL
>>>>>>
>>>>>> 1x6gUC7mzzY6o5Niy1T1YworpQi3qJ5fxhSejRWQ9c0caqokCU9S$
>>>>>>
>>>>>>
>>>>>> I'm curious if anyone has ever worked with it, i.e. fed it an
>>>>>> accessible (fully tagged) PDF file and verified that it renders an
>>>>>> accessible screen reader user experience.
>>>>>> I've seen a couple of examples that look less than accessible but
>>>>>> I found those in the wil and have not verified the PDF files
>>>>>> themselves.
>>>>>> Ultimately I'll have to build this and try it out, but if someone
>>>>>> already has experience with it, I always appreciate knowing what
>>>>>> to expect. ;) Thanks -Birkir
>>>>>> --
>>>>>> Work hard. Have fun. Make history.
>>>>>> >>>>>>
>> >> >> archives athttp://webaim.org/discussion/archives
>> > > > > > > List archives athttp://webaim.org/discussion/archives
>