We can use testing tools to catch up to 40% of the accessibility errors in bulk.
The programmatically catchable errors are usually the ones that are easier to fix. These are highly quantitative errors. We can also automate these evaluations through an API and include it in our CI processes.
- WAVE: this is my favorite; simple to use, advanced, and comes with a browser extension. It gives you an API too.
- aXe: it is an advanced tool with many new functions. It also comes with a browser extension and API.
- Accessibility Insights: catch accessibility errors on Android, web, or Windows.
- Lighthouse: it is a complex testing tool that also catches a11y errors. You can also use it through your developer console.
Commonly, you only need one tool to test, but sometimes it is a good idea to test your sites with more than one tool.