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Re: Any official clarification on Text-only zoom and RWD?


From: Guy Hickling
Date: Feb 25, 2016 6:26AM

Alastair, Jordan, This is in reply to your two requests for an example
site that can handle text-only zoom up to 200%. But Alastair already
has the way to do it - you
mentioned using em measurements for everything, along with suitable media
queries of course.

That is the answer, because em measurements on everything mean the
containers resize on zoom at the same rate as the text they contain, so the
content never breaks out of its containers. I created my own blog site that
way, and it's good for up to 300% text-only zoom in Firefox, with no
horizintal scrolling needed, and other browers that do text only zoom. I
wrote a post Accessible Responsiveness about it, and how to do it, last
year, at http://www.enigmaticweb.com/index.php/blog/accessibleResponsiveness,
and you can zoom it up to 300% to see it working. (I would appreciate any
comments or criticisms you have about the article; there's a form at the

On responsive sites, using em units, at higher zooms the breakpoints
come much earlier; at 200% zoom it may show a tablet layout at almost
desktop screen size!, but that's still ok for the user.
Users have to know​, of course,​ that they must select the "text-only"
option which most browsers have. ​(One post in this thread seemed to
be unaware of that, so for their
reference, ​In Firefox that's a tick box on the View/Zoom submenu, at
the foot of the
popup selection choices, but people with impaired sight would no doubt want
to permanently configure their browsers in the configuration facility.
​ IE also allows it, but if I remember rightly one of the big 5 browsers
didn't do it at least upto last year)​

Guy Hickling