HTML Validator - HTML Validator is a Mozilla extension that adds HTML validation inside Firefox and Mozilla.
Who Can Use - WhoCanUse is a tool that brings attention and understanding to how color contrast can affect different people with visual impairments.
W3C Markup Validation Service - Validates HTML markup of web pages, one at a time.
Two Dots - Sharpen your puzzle solving skills with a challenging game of dot connection.
Rocket Validator - Site-wide Accessibility and HTML validation made easy. With a single click, Rocket Validator will check thousands of web pages on your site for Accessibility and HTML conformance, producing a detailed, actionable report on seconds.
Contraste - Check the accessibility of text against the WCAG.