quick-lint-js finds bugs in JavaScript programs.

Warning: This is pre-release software. quick-lint-js is under active development and is unstable. Use at your own risk.

quick-lint-js finds many bugs, including:

• Using a variable which does not exist
• Assigning to a const variable
• Using await in a non-async function
• Syntax errors

See installation instructions for how to install quick-lint-js' CLI, LSP server, and editor plugins.

See build instructions for how to build quick-lint-js for development.

Bugs and feature requests: file an issue on GitHub

IRC: ask questions in #quick-lint-js on Libera.Chat

Security bug reports (private disclosure): email [email protected]

• Performance. You use quick-lint-js in text editors and IDEs to show bugs as they are written. quick-lint-js must be fast to make feedback responsive.

  • Small design. The less infrastructure and developer conveniences used within quick-lint-js, the less time quick-lint-js wastes due to this bloat.
  • Few features. Features add run-time costs. With fewer features, quick-lint-js gives you feedback sooner.

• High signal. quick-lint-js finds bugs, not nitpicks. You can use quick-lint-js in any project, no matter the size or style.

  • No opinions. quick-lint-js doesn't complain about style issues, like using 'strings' vs "strings". It complains about real bugs which everyone agrees are bugs.
  • No false positives. If quick-lint-js complains, you know it's a bug in your code.
  • No configuration. quick-lint-js works out-of-the-box. You don't need configuration files to tell quick-lint-js what buggy code looks like.