This list below are some web accessibility tools for validating website for accessibility issues:

Accessibility Validation Tools

• WAVE: WAVE is a browser extension that works with Google Chrome and Firefox. WAVE also has a built in contrast checker.
• AXE: AXE is a browser extension that works with Google Chrome and Firefox.
• Siteimprove Accessibility Checker: Siteimprove Accessibility Checker is a Google Chrome only browser extension.

Web Development Quick Check List

• Web Accessibility Development Quick Check List: This is a simple check list as a cheat sheet to help developers get into the habit of developing with accessibility in mind.