Lighthouse

An open-source automated tool developed by Google for auditing web page quality, including performance, accessibility, SEO, and progressive web app compliance. Lighthouse runs in Chrome DevTools, as a browser extension, or via command line, and produces scores from 0-100 for each audit category. For accessibility, Lighthouse uses the axe-core library to check a subset of WCAG 2.1 Level A and AA success criteria. While widely used due to its integration with Chrome, Lighthouse has transparency limitations: it does not explicitly reference which WCAG guidelines it checks, uses a weighted scoring system that can obscure individual issues, and only tests a partial set of axe-core rules. A score of 100 does not indicate full accessibility compliance—manual testing remains essential.