ESLint
A JavaScript linter that finds and reports problematic code patterns, with rules you can configure.
- Stars
- 27.6k
- Forks
- 5.2k
- Licence
- MIT
- Language
- JavaScript
- Last update
- 4 days ago
- Type
- Dev tool
What it is
ESLint is a tool that scans JavaScript (ECMAScript) code and reports patterns that may be problems or bad practice. It works by parsing code into a syntax tree and checking it against rules, and every rule is a pluggable piece you can turn on, off, or adjust. Developers use it to catch mistakes and keep code style consistent across a project.
- Run npx eslint on a file or directory to report problems
- Define rules in an eslint.config.js file and set each to off, warn, or error
- Use a config setup command (npm init @eslint/config@latest) to start a project configuration
- Add plugins to check framework-specific patterns, such as eslint-plugin-react for React semantics
Great for
- JavaScript developers who want automatic checks on their code
- Teams that want consistent rules enforced in a shared configuration
- Projects that need to customize which code patterns are flagged
- Developers working with React who add a React-specific plugin on top
Not ideal for
- People who only want code formatting; the README says Prettier is the formatter and ESLint is a linter
- Users of experimental or non-standard syntax without a suitable parser, since ESLint officially supports only the latest final ECMAScript standard
- Environments that cannot run a supported Node.js version (^20.19.0, ^22.13.0, or >=24)
How to get it
- 1
Install with a package manager
You'll need: Node.js ^20.19.0, ^22.13.0, or >=24 (built with SSL and ICU)
Install and configure ESLint
npm init @eslint/config@latestRun ESLint on a file
npx eslint yourfile.js - 2
Run it
- Make sure Node.js is installed at a supported version
- Run npm init @eslint/config@latest in your project to create a configuration
- Run npx eslint yourfile.js on any file or directory
- Review reported problems and adjust rule levels in eslint.config.js as needed
- 3
Get the most out of it
- Set individual rules to "warn" or "error" in eslint.config.js to control which problems matter
- Use the files pattern in the config to apply different rules to different file types
- Add eslint-plugin-react if you use React and want React-specific checks
- Pair with Prettier for formatting, as the README recommends using both tools together
- For pnpm users, the README suggests a .npmrc with auto-install-peers=true and node-linker=hoisted
Downloads
Strengths
- Highly pluggable: every rule is a plugin and rules can be added at runtime, per the README
- Mature and widely used, with an MIT license and about 27,600 GitHub stars
- Clear three-level severity model (off, warn, error) that controls the exit code
Trade-offs
- Requires a supported Node.js version and, for TypeScript type definitions, TypeScript 5.3 or later
- Does not lock dependency versions by design, so behavior can change as dependencies update
- Parser officially supports only the latest final ECMAScript standard; newer experimental syntax may need other parsers
How it compares
| Project | Stars | Type | Level | Updated | Best for |
|---|---|---|---|---|---|
| eslint (this) | 27.6k | Dev tool | intermediate | 4 days ago | JavaScript developers who want automatic checks on their code |
| typescript-eslint | 16.5k | Dev tool | intermediate | 5 days ago | JavaScript and TypeScript developers who already use ESLint |
| prettier | 52.4k | Dev tool | beginner | 4 days ago | Teams that want one shared code style without writing their own rules |
| standard | 29.4k | Dev tool | beginner | 1.3 years ago | JavaScript projects where the team wants consistent style without debating rules |
| lint-staged | 14.8k | Dev tool | intermediate | 6 days ago | JavaScript or Node.js projects that already use tools like ESLint or Prettier |
| ruff | 50.4k | CLI | beginner | 4 days ago | Python developers who want one tool for linting and formatting |
Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.