Accessibility by the book and by the numbers
There are 50 Success Criteria (SC) at WCAG 2.1 Level AA. 30 are Level A and 20 are Level AA. Some issues are particularly “famous”: they’ve come up in the 2023 WebAIM Million and Intopia’s Top 6 Accessibility Problems in 2022 - Intopia (5 plus a bonus 1).
One way to test for all of these things is to do an Accessibility Audit.
- However! Some of the SC aren’t applicable (they refer to audio and video, which often don’t occur in web application pages).
- And! A few key checks can cover a lot of the issues.
- Which! Means a more accessible and usable experience for our customers.
By Success Criteria
- Doing a QAC will cover between about 30 SC.
- Testing with the keyboard will cover about 10 SC.
- Checking the headings will cover about 3 (important! (but not
- Running axe DevTools will cover between about 20 SC (but
- Testing with a screen reader will cover about 30 SC. (A different 30 to the QAC!)
- Doing both will cover between about 40 SC.
The main things that aren’t covered are audio and video, Reflow (aka “Is it responsive?”), and pointer gestures.
- Doing a QAC covers about 10 of the 12 famous issues from both sources. (It doesn’t cover Reflow and Parsing.)
- Testing with a screen reader covers about 9 of the 12 famous issues. (It doesn’t cover Reflow, Contrast, and Info and Relationships (it should be coded the same as it looks)).
- Doing both will cover
Note: Parsing is “Is the HTML valid?” This rule is removed in WCAG 2.2.
Obligatory Call To Action
If you don’t already have QACing or brief screen reader testing in your process, now’s a good time to add it! 🙃