Axe

An open-source accessibility testing engine developed by Deque Systems that checks web content against WCAG and other accessibility standards. Axe can be integrated into browsers (via browser extensions), development workflows (via axe-core library), and testing frameworks (via axe-playwright, axe-selenium). It identifies accessibility violations with detailed reports including violation type, affected elements, impact level, and remediation guidance. Axe is one of the most widely used automated accessibility testing tools and forms the basis for many other accessibility testing products.