RE: Resizing content on a web page

WCAG 2.1 A and AA 1) requires resize of text up to 200% of the default (SC 1.4.4) and that Content can be presented without loss of information or functionality, and without requiring scrolling in two dimensions for: Vertical scrolling content at a width equivalent to 320 CSS pixels (SC 1.4.10) with separate requirements for vertical writing systems.

Thus, it is not specifically 400% browser zoom that is required – although effectively at 1280 width resolution you should have a viewport of 320CSS pixels if you were to zoom the browser to that.  There are other ways to meet the requirement though in terms of resizing content to 320CSS pixels.

Jonathan

From: Francesco Mammetti <f.mammetti@gmail.com>
Sent: Friday, February 10, 2023 7:14 AM
To: public-low-vision-a11y-tf@w3.org
Subject: Resizing content on a web page

Hi, my name is Francesco Mammetti and I'm a ux designer who works for the Italian public administration, I had two questions to ask you and I thank you in advance if you answer me 1 I read that in WCAG the size to guarantee usability and accessibility in enlargement is 200%, (although I read that many recommend 400%) I wanted to know if I can still take this value into consideration? 2 Is there also a scaling value to decrease? Thanks again.
Francesco