Testing websites for accessibility is a service that is in very high demand. These tools will help you to test web and non-web content for accessibility. As of January, 2018, all of the tools below are free to use. Disclaimer: no automatic tool catches everything. Manual testing is necessary, and information about manual techniques is in the list below as well.
- World Wide Web Consortium Web Accessibility Evaluation Tool List
Part of the Evaluation Resources above, this lets you select the set of accessibility standards that you want to check, languages, page types and other criteria and then shows you tools that fit your needs.
- WAVE Website and Browser Add-ons
- The Paciello Group Colour Contrast Analyser
A small but incredibly flexible tool that lets you select a foreground color and a background color. The tool then tells you the contrast ratio between the two and shows whether the ratio meets Web Content Accessibility Guidelines. The tool will work on web pages as well as Office and PDF files. If you can open something on your computer then this tool will let you check it.