eslint

pluggable JavaScript and TypeScript linter

TLDR

Lint JavaScript files

$ eslint [file.js]

Lint directory recursively

$ eslint [src/]

Fix auto-fixable issues

$ eslint --fix [file.js]

Specify config file

$ eslint -c [.eslintrc.json] [file.js]

Output in specific format

$ eslint -f [json] [file.js]

Create a configuration file interactively

$ npm init @eslint/config

Lint files piped on stdin

$ cat [file.js] | eslint --stdin

ESLint is the standard linting tool for JavaScript and TypeScript. It statically analyzes code to find problems, enforce coding standards, and catch bugs before runtime.Rules are highly configurable. Plugins extend functionality for React, Vue, TypeScript, and other frameworks. The --fix flag automatically corrects many issues.ESLint integrates with editors and CI systems, making it central to JavaScript development workflows.

PARAMETERS

FILES

Files or directories to lint.

--fix

Automatically fix problems.

-c, --config FILE

Configuration file.

-f, --format FORMAT

Output format.

--cache

Only check files that changed since the last run.

--quiet

Report errors only, suppressing warnings.

--max-warnings N

Exit with an error if more than N warnings are found.

--no-eslintrc

Ignore configuration files (legacy config only).

--rulesdir DIR

Load additional custom rules from a directory (deprecated).

--stdin

Lint source read from standard input.

--help

Display help information.

CONFIGURATION

eslint.config.js (flat config)

The default configuration file since ESLint v9. It exports an array of config objects defining files, rules, plugins and language options. Also available as eslint.config.mjs or eslint.config.cjs.

.eslintrc.js / .eslintrc.json / .eslintrc.yml (legacy)

The pre-v9 "eslintrc" format. Deprecated and no longer searched for by default in v9, and slated for removal in v10.

INSTALL

sudo pacman -S eslint

brew install eslint

nix profile install nixpkgs#eslint

CAVEATS

Since ESLint v9 the flat config (eslint.config.js) is the default and the legacy .eslintrc format, the --ext flag, --no-eslintrc and the built-in `--init` command have been removed or replaced; use `npm init @eslint/config` to scaffold a config. Plugin compatibility varies between the two config systems. Large codebases benefit from --cache.

HISTORY

ESLint was created by Nicholas C. Zakas in 2013 as a more pluggable and configurable alternative to JSHint. It became the dominant JavaScript linter due to its extensibility.

RESOURCES

Source code · Homepage · Documentation