There's no doubt that accessibility is important. WCAG 1.0 became a W3C Recommendation nearly 20 years ago, and WCAG 2.1 is soon to be a Candidate Recommendation. Our community has been talking about accessibility for years, and each major release of Drupal is more accessible than the last. Nevertheless, we find it hard to make the time to thoroughly test our work, and like all testing, when crunch time comes, if it's not automated, it may not happen.

We can drastically reduce the effort involved in accessibility testing, and reduce human errors, by automating some tests as part of a standard Continuous Integration (CI) process. There are a number of paid and free tools available on the market, and we've chosen three to compare.

Google's Litehouse (using Deque's aXe-core rules engine)
Open source
Free
Includes tests for performance, progressive web apps, and more
Tenon.io
Software as a service
30-day trial
Growing in popularity,
WAVE API (from WebAIM.org)
Software as a service and self-hosted
100 free credits
From the makers of the popular browser extension (http://wave.webaim.org/extension/)
What you will learn:

What is automated accessibility testing, and what can be tested
How to integrate Lighthouse, Tenon.io and WAVE API with your CI process
What are the benefits of Lighthouse
What are the benefits of Tenon.io
What are the benefits of WAVE API


Slides available at

https://laura-johnson.github.io/accessibility-presentation/