webhintio/hint

webhint is a tool that scans websites and reports problems with the code, similar to how a spelling checker scans text for errors. It looks specifically at things that matter for website quality: accessibility for people using assistive technologies, page loading speed, cross-browser compatibility, and general best practices around security and standards. Rather than enforcing a single fixed set of rules, it is designed to be customizable so teams can pick which checks apply to their project. It can be used in three ways. From the command line, you can point it at any URL and get a report without installing anything permanently, using a single npx command. There is also a browser extension that lets you analyze a page while you are viewing it, and a VS Code extension that surfaces hints while you are writing code in your editor. All three use the same underlying hint engine. The project is organized as a monorepo, meaning all of the individual components including the CLI, the browser extension, the VS Code extension, the individual hint rules, the output formatters, and the parsers live in one repository and are published as separate npm packages. Contributors working on new hints or other components can build the full project locally using yarn. Getting started requires Node.js version 14 or later. The quickest way to try it is to run npx hint followed by any website address. For a permanent setup in a project, it can be added as a development dependency via npm or yarn and wired into the build script. The source is open under the Apache 2.0 license and the project is part of the OpenJS Foundation.