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Re: Does PDF.JS render acccessible PDF experience?

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From: Steve Green
Date: Jun 19, 2024 8:30AM

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 can't set the size of a text frame and the text doesn't 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 – it's not in the Properties or anywhere else. NVDA can't 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 it's clear that people just use whatever the default reader turns out to be, and it's 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 wives’ tales about which reader application is best, almost all of which are wrong.

Steve Green
Managing Director
Test Partners Ltd