> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/eslint/eslint/llms.txt
> Use this file to discover all available pages before exploring further.

# Command Line Interface

> Learn how to use ESLint from the command line with all available options and flags

# Command Line Interface

The ESLint Command Line Interface (CLI) lets you execute linting from the terminal. The CLI has a variety of options that you can pass to configure ESLint.

## Basic Usage

ESLint requires Node.js for installation. Most users use `npx` to run ESLint on the command line:

```bash theme={null}
npx eslint [options] [file|dir|glob]*
```

<CodeGroup>
  ```bash Run on two files theme={null}
  npx eslint file1.js file2.js
  ```

  ```bash Run on directory theme={null}
  npx eslint lib/**
  ```

  ```bash Run with config theme={null}
  npx eslint -c my.config.js src/
  ```
</CodeGroup>

<Note>
  When passing a glob as a parameter, it is expanded by your shell. Quote your parameter if you need it to run in Windows: `npx eslint "lib/**"`
</Note>

## CLI Options Reference

### Basic Configuration

<AccordionGroup>
  <Accordion title="--config, -c" icon="gear">
    Use a specific configuration file instead of the default `eslint.config.js`.

    ```bash theme={null}
    npx eslint -c ~/my.eslint.config.js file.js
    ```

    **Type:** String (path to file)
  </Accordion>

  <Accordion title="--no-config-lookup" icon="ban">
    Disables automatic lookup for `eslint.config.js` files.

    ```bash theme={null}
    npx eslint --no-config-lookup file.js
    ```
  </Accordion>

  <Accordion title="--inspect-config" icon="magnifying-glass">
    Opens the config inspector to visualize your configuration.

    ```bash theme={null}
    npx eslint --inspect-config
    ```

    This runs `@eslint/config-inspector` to help you understand what your configuration is doing.
  </Accordion>

  <Accordion title="--ext" icon="file">
    Specify additional file extensions to lint beyond the default `.js`, `.mjs`, and `.cjs`.

    ```bash theme={null}
    npx eslint . --ext .ts
    npx eslint . --ext .ts --ext .tsx
    npx eslint . --ext .ts,.tsx
    ```

    **Type:** String or Array
    **Default:** `.js`, `.mjs`, `.cjs`
  </Accordion>

  <Accordion title="--global" icon="globe">
    Define global variables so they are not flagged as undefined by the `no-undef` rule.

    ```bash theme={null}
    npx eslint --global require,exports:true file.js
    npx eslint --global require --global exports:true
    ```

    Append `:true` to a variable name to allow writes to that global.
  </Accordion>

  <Accordion title="--parser" icon="code">
    Specify the parser to be used by ESLint.

    ```bash theme={null}
    npx eslint --parser @typescript-eslint/parser file.ts
    ```

    **Default:** `espree`
  </Accordion>

  <Accordion title="--parser-options" icon="sliders">
    Specify parser options as key-value pairs.

    ```bash theme={null}
    echo '3 ** 4' | npx eslint --stdin --parser-options ecmaVersion:7
    ```

    **Format:** `key:value` pairs
  </Accordion>
</AccordionGroup>

### Rules and Plugins

<AccordionGroup>
  <Accordion title="--plugin" icon="puzzle-piece">
    Specify plugins to load. You can optionally omit the `eslint-plugin-` prefix.

    ```bash theme={null}
    npx eslint --plugin jquery file.js
    npx eslint --plugin eslint-plugin-mocha file.js
    ```

    <Warning>
      You must install the plugin using npm before using this option.
    </Warning>
  </Accordion>

  <Accordion title="--rule" icon="ruler">
    Specify rules to be used. These are merged with configuration file rules.

    ```bash theme={null}
    npx eslint --rule 'quotes: [error, double]' file.js
    npx eslint --rule 'guard-for-in: error' --rule 'brace-style: [error, 1tbs]' file.js
    npx eslint --rule 'jquery/dollar-sign: error' file.js
    ```

    **Format:** Uses [levn](https://github.com/gkz/levn#levn--) format

    <Tip>
      Combine with `--no-config-lookup` to only apply command line rules.
    </Tip>
  </Accordion>
</AccordionGroup>

### Fix Problems

<AccordionGroup>
  <Accordion title="--fix" icon="wrench">
    Automatically fix problems. Fixes are made to the actual files.

    ```bash theme={null}
    npx eslint --fix file.js
    ```

    <Warning>
      * This option throws an error when code is piped to ESLint
      * Not all problems are fixable
      * Has no effect on code that uses a processor (unless the processor opts in)
    </Warning>
  </Accordion>

  <Accordion title="--fix-dry-run" icon="flask">
    Fix problems without saving changes to the file system.

    ```bash theme={null}
    getSomeText | npx eslint --stdin --fix-dry-run --format json
    ```

    Useful for editor integrations that need to autofix text without saving.
  </Accordion>

  <Accordion title="--fix-type" icon="filter">
    Specify the types of fixes to apply.

    ```bash theme={null}
    npx eslint --fix --fix-type suggestion .
    npx eslint --fix --fix-type suggestion --fix-type problem .
    npx eslint --fix --fix-type suggestion,layout .
    ```

    **Options:**

    * `problem` - fix potential errors in the code
    * `suggestion` - apply fixes that improve code
    * `layout` - apply fixes that don't change the AST
    * `directive` - apply fixes to inline directives
  </Accordion>
</AccordionGroup>

### Ignore Files

<AccordionGroup>
  <Accordion title="--no-ignore" icon="eye">
    Disables excluding files from `--ignore-pattern` and the `ignores` configuration property.

    ```bash theme={null}
    npx eslint --no-ignore file.js
    ```
  </Accordion>

  <Accordion title="--ignore-pattern" icon="ban">
    Specify patterns of files to ignore (uses minimatch syntax).

    ```bash theme={null}
    npx eslint --ignore-pattern "/lib/" --ignore-pattern "/src/vendor/*" .
    ```

    <Note>
      Quote your patterns to avoid shell interpretation of glob patterns.
    </Note>
  </Accordion>
</AccordionGroup>

### Input/Output

<AccordionGroup>
  <Accordion title="--stdin" icon="terminal">
    Lint code provided on STDIN instead of from files.

    ```bash theme={null}
    cat myFile.js | npx eslint --stdin
    ```
  </Accordion>

  <Accordion title="--stdin-filename" icon="file-signature">
    Specify a filename to process STDIN as.

    ```bash theme={null}
    cat myFile.js | npx eslint --stdin --stdin-filename myfile.js
    ```

    Useful when processing files from STDIN and you have rules that depend on the filename.
  </Accordion>

  <Accordion title="--output-file, -o" icon="file-export">
    Write the output to a specified file.

    ```bash theme={null}
    npx eslint -o ./test/test.html
    ```
  </Accordion>

  <Accordion title="--format, -f" icon="paint-brush">
    Specify the output format for the console.

    ```bash theme={null}
    npx eslint --format json file.js
    npx eslint -f ./customformat.js file.js
    npx eslint -f pretty file.js
    ```

    **Built-in formatters:**

    * `stylish` (default)
    * `json`
    * `json-with-metadata`
    * `html`
  </Accordion>

  <Accordion title="--color / --no-color" icon="palette">
    Force enabling or disabling of colorized output.

    ```bash theme={null}
    npx eslint --color file.js | cat
    npx eslint --no-color file.js
    ```
  </Accordion>
</AccordionGroup>

### Handle Warnings

<AccordionGroup>
  <Accordion title="--quiet" icon="volume-mute">
    Report errors only - disables reporting on warnings.

    ```bash theme={null}
    npx eslint --quiet file.js
    ```

    Only rules set to `error` will be run; rules set to `warn` are disabled.
  </Accordion>

  <Accordion title="--max-warnings" icon="triangle-exclamation">
    Specify a warning threshold to force ESLint to exit with an error status.

    ```bash theme={null}
    npx eslint --max-warnings 10 file.js
    ```

    **Type:** Integer
    **Default:** `-1` (unlimited)

    <Info>
      When used with `--quiet`, rules marked as warn still run but are not reported.
    </Info>
  </Accordion>
</AccordionGroup>

### Caching

<AccordionGroup>
  <Accordion title="--cache" icon="database">
    Only check changed files. Dramatically improves performance by storing info about processed files.

    ```bash theme={null}
    npx eslint --cache file.js
    ```

    **Default cache location:** `.eslintcache`

    <Tip>
      Autofixed files are not placed in the cache. Subsequent linting that doesn't trigger an autofix will place it in the cache.
    </Tip>
  </Accordion>

  <Accordion title="--cache-location" icon="folder">
    Specify the path to the cache file or directory.

    ```bash theme={null}
    npx eslint "src/**/*.js" --cache --cache-location "/Users/user/.eslintcache/"
    ```

    <Note>
      Add a trailing `/` on \*nix systems or `\` on Windows if specifying a directory.
    </Note>
  </Accordion>

  <Accordion title="--cache-strategy" icon="diagram-project">
    Strategy for detecting changed files in the cache.

    ```bash theme={null}
    npx eslint "src/**/*.js" --cache --cache-strategy content
    ```

    **Options:**

    * `metadata` (default) - uses file modification time
    * `content` - uses file content hash

    <Tip>
      Use `content` strategy for git operations where modification time changes but content doesn't.
    </Tip>
  </Accordion>
</AccordionGroup>

### Miscellaneous

<AccordionGroup>
  <Accordion title="--init" icon="wand-magic-sparkles">
    Run config initialization wizard.

    ```bash theme={null}
    npx eslint --init
    ```

    Runs `npm init @eslint/config` to help create an `eslint.config.js` file.
  </Accordion>

  <Accordion title="--debug" icon="bug">
    Output debugging information to the console.

    ```bash theme={null}
    npx eslint --debug test.js
    ```

    Useful when you're seeing a problem and having a hard time pinpointing it.
  </Accordion>

  <Accordion title="--help, -h" icon="circle-question">
    Output the help menu.

    ```bash theme={null}
    npx eslint --help
    ```
  </Accordion>

  <Accordion title="--version, -v" icon="tag">
    Output the current ESLint version.

    ```bash theme={null}
    npx eslint --version
    ```
  </Accordion>

  <Accordion title="--print-config" icon="print">
    Output the configuration to be used for a file.

    ```bash theme={null}
    npx eslint --print-config file.js
    ```

    No linting is performed when this flag is present.
  </Accordion>

  <Accordion title="--stats" icon="chart-line">
    Add detailed performance statistics to the lint results.

    ```bash theme={null}
    npx eslint --stats --format json file.js
    ```

    Includes parse, fix, and lint times per rule.
  </Accordion>

  <Accordion title="--env-info" icon="info-circle">
    Output execution environment information.

    ```bash theme={null}
    npx eslint --env-info
    ```

    Displays Node.js, npm, and ESLint version information.
  </Accordion>

  <Accordion title="--concurrency" icon="gears">
    Control the number of worker threads used to lint files.

    ```bash theme={null}
    npx eslint --concurrency auto
    npx eslint --concurrency 4
    ```

    **Options:**

    * `off` (default) - lint in main thread
    * `auto` - determine best setting automatically
    * `<number>` - specific number of threads
  </Accordion>
</AccordionGroup>

## Exit Codes

When linting files, ESLint exits with one of the following exit codes:

<CardGroup cols={3}>
  <Card title="Exit Code 0" icon="circle-check" color="#10b981">
    Linting successful with no errors. Warnings are at most equal to `--max-warnings` value.
  </Card>

  <Card title="Exit Code 1" icon="circle-xmark" color="#f59e0b">
    Linting successful but at least one error found, or warnings exceed `--max-warnings`.
  </Card>

  <Card title="Exit Code 2" icon="circle-exclamation" color="#ef4444">
    Linting unsuccessful due to configuration problem or internal error.
  </Card>
</CardGroup>

## Examples

<Tabs>
  <Tab title="Basic">
    ```bash theme={null}
    # Lint all JavaScript files in the current directory
    npx eslint .

    # Lint specific files
    npx eslint file1.js file2.js

    # Lint with a specific config
    npx eslint -c my-config.js src/
    ```
  </Tab>

  <Tab title="With Fixing">
    ```bash theme={null}
    # Auto-fix all fixable issues
    npx eslint --fix .

    # Fix only specific types
    npx eslint --fix --fix-type suggestion src/

    # Dry run to see what would be fixed
    npx eslint --fix-dry-run --format json src/
    ```
  </Tab>

  <Tab title="Performance">
    ```bash theme={null}
    # Use caching for faster linting
    npx eslint --cache src/

    # Use content-based caching
    npx eslint --cache --cache-strategy content src/

    # Enable multithreading
    npx eslint --concurrency auto src/
    ```
  </Tab>

  <Tab title="CI/CD">
    ```bash theme={null}
    # Fail on any warnings
    npx eslint --max-warnings 0 src/

    # Only report errors
    npx eslint --quiet src/

    # Output JSON for processing
    npx eslint --format json --output-file results.json src/
    ```
  </Tab>
</Tabs>

## Related Resources

<CardGroup cols={2}>
  <Card title="Configuration" icon="gear" href="./configuration">
    Learn how to configure ESLint using eslint.config.js
  </Card>

  <Card title="Formatters" icon="paint-brush" href="./formatters">
    Explore different output format options
  </Card>

  <Card title="Ignoring Code" icon="ban" href="./ignoring-code">
    Learn how to ignore files and patterns
  </Card>

  <Card title="Core Concepts" icon="book" href="./core-concepts">
    Understand ESLint fundamentals
  </Card>
</CardGroup>