---
id: configuration
title: Configuration File
---

Prettier uses [cosmiconfig](https://github.com/davidtheclark/cosmiconfig) for configuration file support. This means you can configure prettier via:

- A `.prettierrc` file, written in YAML or JSON, with optional extensions: `.yaml/.yml/.json`.
- A `.prettierrc.toml` file, written in TOML (the `.toml` extension is _required_).
- A `prettier.config.js` or `.prettierrc.js` file that exports an object.
- A `"prettier"` key in your `package.json` file.

The configuration file will be resolved starting from the location of the file being formatted, and searching up the file tree until a config file is (or isn't) found.

The options to the configuration file are the same as the [API options](options.md).

## Basic Configuration

JSON:

```json
{
  "trailingComma": "es5",
  "tabWidth": 4,
  "semi": false,
  "singleQuote": true
}
```

JS:

```js
// prettier.config.js or .prettierrc.js
module.exports = {
  trailingComma: "es5",
  tabWidth: 4,
  semi: false,
  singleQuote: true
};
```

YAML:

```yaml
# .prettierrc or .prettierrc.yaml
trailingComma: "es5"
tabWidth: 4
semi: false
singleQuote: true
```

TOML:

```toml
# .prettierrc.toml
trailingComma = "es5"
tabWidth = 4
semi = false
singleQuote = true
```

## Configuration Overrides

Prettier borrows eslint's [override format](http://eslint.org/docs/user-guide/configuring#example-configuration). This allows you to apply configuration to specific files.

JSON:

```json
{
  "semi": false,
  "overrides": [
    {
      "files": "*.test.js",
      "options": {
        "semi": true
      }
    }
  ]
}
```

YAML:

```yaml
semi: false
overrides:
  - files: "*.test.js"
    options:
      semi: true
```

`files` is required for each override, and may be a string or array of strings. `excludeFiles` may be optionally provided to exclude files for a given rule, and may also be a string or array of strings.

## Setting the [parser](options.md#parser) option

By default, Prettier automatically infers which parser to use based on the input file extension. Combined with `overrides` you can teach Prettier how to parse files it does not recognize.

For example, to get Prettier to format its own `.prettierrc` file, you can do:

```json
{
  "overrides": [
    {
      "files": ".prettierrc",
      "options": { "parser": "json" }
    }
  ]
}
```

You can also switch to the `flow` parser instead of the default `babel` for .js files:

```json
{
  "overrides": [
    {
      "files": "*.js",
      "options": {
        "parser": "flow"
      }
    }
  ]
}
```

**Note:** _Never_ put the `parser` option at the top level of your configuration. _Only_ use it inside `overrides`. Otherwise you effectively disable Prettier's automatic file extension based parser inference. This forces Prettier to use the parser you specified for _all_ types of files – even when it doesn't make sense, such as trying to parse a CSS file as JavaScript.

## Configuration Schema

If you'd like a JSON schema to validate your configuration, one is available here: http://json.schemastore.org/prettierrc.
