Automated and manual

Your approach for testing websites and applications for accessibility compliance involves different kinds of testing methods, tools, and testers. You need a combination for better testing coverage. 

• Automated testing. Checker tools like Siteimprove and WAVE
• Manual testing. Humans perform the checks and typically find more issues than automated testing.

Check out Siteimprove's Accessibility 101 webinars (MyAccess login required) for a primary introduction to testing and the importance of combining automated testing with manual testing.

Test early, test often

• Checking and ensuring accessibility is for every stage of the product life cycle, but it is most cost-effective in  development.
• A reiterative approach to testing and correcting can give you balance. Trying to test and fix all at once is not practical. The biggest misconception is that Accessibility is applied – it is an integral part of the creation and website management process.