Lib.rs

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#html #seo #html5

app html-lint

Your one-stop shop for HTML linting activities

Owned by emmabastas.

1 unstable release

Uses new Rust 2024

0.1.0 Nov 15, 2025

#4 in Accessibility

AGPL-3.0-or-later

3.5MB
75K SLoC

C 75K SLoC // 0.2% comments Rust 319 SLoC // 0.1% comments

html-lint — Your one-stop shop for HTML linting activities

Whether you're using a templating engine for your server-side rendering, a frontend framework for your SPA, or making a good ol static website: If there's HTML involved, you can lint it using html-lint!

There are two ways of using html-lint

  1. In the terminal: Give the cli-app files to lint and it will give you a report.
  2. In the browser: html-lint can analyses the HTML in the website itself.
Use of html-lint from the CLI on jamstack.org: HTML elements that break rules, like a link opening in a new tab are reported by the CLI tool along with a description of the error and source location Use of html-lint in the browser on jamstack.org: HTML elements that break rules, like a link opening in a new tab are marked in red, and there is a sidebar listing all linting errors

Why not use <my favorite HTML linter> instead?

There are many nice HTML linters out there, however html-lint tries to be something I have not seen elsewhere:

  • Universal. Many html linters are tied to a specific ecosystem: djlint is tied to pip and is for HTML templates only, html-eslint is tied to NodeJS and HTML-in-JS. With html-lint you can install it with pip for your templates on Monday, and then use the same tool via npm for React on Tuesday.
  • zero-config, works for you. html-lint comes with sane defaults so you can focus on making good accessible HTML and not fuss about with configuration. There is always the option of customizing though.
  • Use it everywhere. The mix of simultaneously working in the terminal and on the browser isn't something I've seen elsewhre.

Use in the CLI

Installing

  • Prebuilt binaries in the dist/cli folder.
  • npm npm install --save-dev @emmabastas/html-lint-cli
  • pip pip install html-lint

Usage

Lint all HTML and handlebars files in src.

html-lint src/**/*.html src/**/*.html src/**/*.hbs

More options with html-lint --help.

Use in the browser

Fastest: Use the reverse proxy

Go to html-lint.notadev.net to lint any website.

Add <script> tag

Add <script src="https://cdnjs.cloudflare.com/TODO"></script> inside the <head> of any page you want linted in the browser. You can conditionally include the script tag in development only. Te above script tag uses cdnjs.com to deliver the JS, if you want to host it yourself you can find minified JS bundles in dist/jsbundles.

npm package

If you're working on a frontend with npm you can install the npm package with npm install --save-dev @emmabastas/html-lint-browser, you then run it with

TODO

You only want this to run in development, and so how you do that depends on what bundler you're using.

Configuring

TODO

Contributing

Please contribute <3. There are many ways to do so

  • Let me know you appreciate this tool: Send me an email or star this repo, makes me really happy!
  • Open issues with bugs or things that you want implemented.
  • Add/improve linting rules. See /rules/rules.yaml for further information.
  • Work on the CLI. See /cli/README.md for further information.
  • TODO more.

License & Acknowledgments

The initial set of linting-rules where adapted from a11y.css. Without that project this project would probably not be, so huge shoutout <3.

The following files belong to the duktape.org project and are licensed under the MIT license.

The project uses uses some icons from CSS＊GG. Whenever you see an HTML element with a class-name prefixed by gg- that icon is from CSS＊GG.

All other code in this repository is owned by each respective contributor and licensed under the GNU Affero General Public License version 3 or later (AGPL-3.0-or-later). The license is found in LICENSE.

Dependencies

~16–31MB
~517K SLoC