CI/CD

Lighthouse CI
💎 pipeline tool
More information on setting Lighthouse CI up can be found here.
aXe Core CI
💎 pipeline tool
pa11y
💎 pipeline tool

Automated

Here are five automated tools that are used frequently for accessibility testing:

Chrome and Firefox Accessibility Inspector tab in DevTools
Lighthouse
You can run Lighthouse in Chrome Dev Tools without downloading an extension. Just click on the 'Lighthouse' tab. You can generate an Accessibility report for Mobile and for Desktop.
axe Dev Tools
💎 browser extension
The axe Dev Tools extension, once installed, can be accessed from Chrome Dev Tools. Just click on the 'axe DevTools' tab. You can scan the whole page for free. Automatic issues will be shown, with the code displayed and links to 'more info' about the issue.
SiteImprove
💎 browser extension
WAVE
💎 browser extension

Here are some extra tools that are useful for accessibility testing:

SiteImprove (Paid version)
Jisc have several websites checked by the paid for version of SiteImprove. This can flag manual issues and then provide guidance on how to fix the issues. Speak to Dave Carter (Test Team Lead) if you are interested in your site being added to the SiteImprove monitoring platform.
WebAIM Colour Contrast Checker
Check the background and foreground colours on your site to make sure they pass WCAG standards. This tool also functions as a basic API.
Microsoft Accessibility Insights for Web
💎 browser extension
This will guide you through a manual accessibility assessment. This guidance from the government takes you through using Accessibility Insights.