A lot of accessibility issues have to be taken on an individual basis, so good, publicly available resources tend to be hard to come by. The authoritative (albeit very terse) resource for web accessibility is WCAG: https://www.w3.org/WAI/WCAG21/quickref/?versions=2.1&levels=...

One tool I'd suggest looking into when getting started is Accessibility Insights for Web. A team at Microsoft developed a free, OSS browser extension for automatically detecting most common accessibility issues on your site: https://accessibilityinsights.io/docs/web/overview

Disclaimer: I do work at Microsoft, but my only affiliation with Accessibility Insights is as a happy customer :)

I was trying out the beta and canary versions of the new Edge and installed Accessibility Insights and was pretty impressed.

I immediately thought: how come none of the other browser vendors have something like this after all of this time?

Firefox has an accessibility inspector: https://developer.mozilla.org/en-US/docs/Tools/Accessibility...

Google develops Lighthouse, which, although an extension, I believe includes some a11y checks: https://developers.google.com/web/tools/lighthouse/

Similarly, Mozilla also promoted Webhint: https://webhint.io/ (which is cross-browser)

I'd also recommend Khan Academy's tota11y, which just works as a bookmarklet: https://khan.github.io/tota11y/

I’ve collected a bunch of accessibility resources over the years, from colour apps to guidelines. Hopefully you’ll find it useful: https://www.uxlift.org/topics/accessibility

Modern FE tooling, for all the hate it (sometimes deservedly) gets, has some pretty great a11y stuff, eg my react projects use `eslint-plugin-jsx-a11y`, and devtools / lighthouse supports accessibility audits...

The UK government design system site is a good source for this kind of information [0].

[0] https://design-system.service.gov.uk