Axe
https://www.deque.com/axe/
Axe, by Deque Systems, is a family of tools that enables teams to test the accessibility of web, Android and iOS applications throughout the development cycle, with Chrome and Firefox extensions available.
Pa11y
https://pa11y.org/
Pa11y’s free and open-source tools include a useful command-line interface for testing loaded web pages for issues, in addition to a Dashboard for graphically tracking daily performance trends over time.
WAVE Web Accessibility Tool
https://wave.webaim.org/
WAVE comprises accessibility evaluation tools including an online URL checker, browser-based extensions, plus site-wide APIs and solutions. Pope Tech is an enterprise-level system, with WAVE Runner being a paid dataanalysis service.
VisibleThread
http://www.visiblethread.com
Geared towards optimising content for clearer, more engaging communications across the board, VisibleThread provides measurable insights around web auditing of spelling, link checking, keyword discovery, readability…