prettier/docs/options.md

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---
id: options
title: Options
---
Prettier ships with a handful of customizable format options, usable in both the CLI and API.
## Print Width
Specify the line length that the printer will wrap on.
> **For readability we recommend against using more than 80 characters:**
>
> In code styleguides, maximum line length rules are often set to 100 or 120. However, when humans write code, they don't strive to reach the maximum number of columns on every line. Developers often use whitespace to break up long lines for readability. In practice, the average line length often ends up well below the maximum.
>
> Prettier, on the other hand, strives to fit the most code into every line. With the print width set to 120, prettier may produce overly compact, or otherwise undesirable code.
>
> See the [print width rationale](rationale.md#print-width) for more information.
| Default | CLI Override | API Override |
| ------- | --------------------- | ------------------- |
| `80` | `--print-width <int>` | `printWidth: <int>` |
(If you don't want line wrapping when formatting Markdown, you can set the [Prose Wrap](#prose-wrap) option to disable it.)
## Tab Width
Specify the number of spaces per indentation-level.
| Default | CLI Override | API Override |
| ------- | ------------------- | ----------------- |
| `2` | `--tab-width <int>` | `tabWidth: <int>` |
## Tabs
Indent lines with tabs instead of spaces.
| Default | CLI Override | API Override |
| ------- | ------------ | ----------------- |
| `false` | `--use-tabs` | `useTabs: <bool>` |
(Tabs will be used for _indentation_ but Prettier uses spaces to _align_ things, such as in ternaries.)
## Semicolons
Print semicolons at the ends of statements.
Valid options:
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- `true` - Add a semicolon at the end of every statement.
- `false` - Only add semicolons at the beginning of lines that [may introduce ASI failures](rationale.md#semicolons).
| Default | CLI Override | API Override |
| ------- | ------------ | -------------- |
| `true` | `--no-semi` | `semi: <bool>` |
## Quotes
Use single quotes instead of double quotes.
Notes:
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- Quotes in JSX will always be double and ignore this setting.
- If the number of quotes outweighs the other quote, the quote which is less used will be used to format the string - Example: `"I'm double quoted"` results in `"I'm double quoted"` and `"This \"example\" is single quoted"` results in `'This "example" is single quoted'`.
See the [strings rationale](#rationale.md#strings) for more information.
| Default | CLI Override | API Override |
| ------- | ---------------- | --------------------- |
| `false` | `--single-quote` | `singleQuote: <bool>` |
## Trailing Commas
Print trailing commas wherever possible when multi-line. (A single-line array, for example, never gets trailing commas.)
Valid options:
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- `"none"` - No trailing commas.
- `"es5"` - Trailing commas where valid in ES5 (objects, arrays, etc.)
- `"all"` - Trailing commas wherever possible (including function arguments). This requires node 8 or a [transform](https://babeljs.io/docs/plugins/syntax-trailing-function-commas/).
| Default | CLI Override | API Override |
| -------- | ------------------------------------------------------ | ------------------------------------------------------ |
| `"none"` | <code>--trailing-comma <none&#124;es5&#124;all></code> | <code>trailingComma: "<none&#124;es5&#124;all>"</code> |
## Bracket Spacing
Print spaces between brackets in object literals.
Valid options:
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- `true` - Example: `{ foo: bar }`.
- `false` - Example: `{foo: bar}`.
| Default | CLI Override | API Override |
| ------- | ---------------------- | ------------------------ |
| `true` | `--no-bracket-spacing` | `bracketSpacing: <bool>` |
## JSX Brackets
Put the `>` of a multi-line JSX element at the end of the last line instead of being alone on the next line (does not apply to self closing elements).
Valid options:
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- `true` - Example:
<!-- prettier-ignore -->
```
<button
className="prettier-class"
id="prettier-id"
onClick={this.handleClick}>
Click Here
</button>
```
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- `false` - Example:
<!-- prettier-ignore -->
```
<button
className="prettier-class"
id="prettier-id"
onClick={this.handleClick}
>
Click Here
</button>
```
| Default | CLI Override | API Override |
| ------- | ------------------------- | ---------------------------- |
| `false` | `--jsx-bracket-same-line` | `jsxBracketSameLine: <bool>` |
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## Arrow Function Parentheses
_available in v1.9.0+_
Include parentheses around a sole arrow function parameter.
Valid options:
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- `"avoid"` - Omit parens when possible. Example: `x => x`
- `"always"` - Always include parens. Example: `(x) => x`
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| Default | CLI Override | API Override |
| --------- | ----------------------------------------------- | ----------------------------------------------- |
| `"avoid"` | <code>--arrow-parens <avoid&#124;always></code> | <code>arrowParens: "<avoid&#124;always>"</code> |
## Range
Format only a segment of a file.
These two options can be used to format code starting and ending at a given character offset (inclusive and exclusive, respectively). The range will extend:
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- Backwards to the start of the first line containing the selected statement.
- Forwards to the end of the selected statement.
These options cannot be used with `cursorOffset`.
| Default | CLI Override | API Override |
| ---------- | --------------------- | ------------------- |
| `0` | `--range-start <int>` | `rangeStart: <int>` |
| `Infinity` | `--range-end <int>` | `rangeEnd: <int>` |
## Parser
Specify which parser to use.
Prettier automatically infers the parser from the input file path, so you shouldn't have to change this setting.
Both the `babylon` and `flow` parsers support the same set of JavaScript features (including Flow type annotations). They might differ in some edge cases, so if you run into one of those you can try `flow` instead of `babylon`.
Valid options:
- `"babylon"` (via [@babel/parser](https://github.com/babel/babel/tree/master/packages/babel-parser))
- `"flow"` (via [flow-parser](https://github.com/facebook/flow/tree/master/src/parser))
- `"typescript"` (via [typescript-estree](https://github.com/JamesHenry/typescript-estree)) _Since v1.4.0_
- `"css"` (via [postcss-scss](https://github.com/postcss/postcss-scss) and [postcss-less](https://github.com/shellscape/postcss-less), autodetects which to use) _Since v1.7.1_
- `"scss"` (same parsers as `"css"`, prefers postcss-scss) _Since v1.7.1_
- `"less"` (same parsers as `"css"`, prefers postcss-less) _Since v1.7.1_
- `"json"` (via [@babel/parser parseExpression](https://babeljs.io/docs/en/next/babel-parser.html#babelparserparseexpressioncode-options)) _Since v1.5.0_
- `"json5"` (same parser as `"json"`, but outputs as [json5](https://json5.org/)) _Since v1.13.0_
- `"json-stringify"` (same parser as `"json"`, but outputs like `JSON.stringify`) _Since v1.13.0_
- `"graphql"` (via [graphql/language](https://github.com/graphql/graphql-js/tree/master/src/language)) _Since v1.5.0_
- `"markdown"` (via [remark-parse](https://github.com/wooorm/remark/tree/master/packages/remark-parse)) _Since v1.8.0_
- `"vue"` (uses several parsers) _Since 1.10.0_
- `"yaml"` (via [yaml](https://github.com/eemeli/yaml) and [yaml-unist-parser](https://github.com/ikatyang/yaml-unist-parser)) _Since 1.14.0_
<!-- TODO: Uncomment and move below "markdown" above when 1.15.0 is released.
- `"mdx"` (same parser as `"markdown"`, with some custom overrides) _Since 1.15.0_
-->
[Custom parsers](api.md#custom-parser-api) are also supported. _Since v1.5.0_
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| Default | CLI Override | API Override |
| ------- | ----------------------------------------------- | ---------------------------------------------------------- |
| None | `--parser <string>`<br />`--parser ./my-parser` | `parser: "<string>"`<br />`parser: require("./my-parser")` |
Note: the default value was `"babylon"` until v1.13.0.
## FilePath
Specify the input filepath. This will be used to do parser inference.
For example, the following will use the CSS parser:
```bash
cat foo | prettier --stdin-filepath foo.css
```
| Default | CLI Override | API Override |
| ------- | --------------------------- | ---------------------- |
| None | `--stdin-filepath <string>` | `filepath: "<string>"` |
## Require pragma
_available in v1.7.0+_
Prettier can restrict itself to only format files that contain a special comment, called a pragma, at the top of the file. This is very useful when gradually transitioning large, unformatted codebases to prettier.
For example, a file with the following as its first comment will be formatted when `--require-pragma` is supplied:
```js
/**
* @prettier
*/
```
or
```js
/**
* @format
*/
```
| Default | CLI Override | API Override |
| ------- | ------------------ | ----------------------- |
| `false` | `--require-pragma` | `requirePragma: <bool>` |
## Insert Pragma
_available in v1.8.0+_
Prettier can insert a special @format marker at the top of files specifying that the file has been formatted with prettier. This works well when used in tandem with the `--require-pragma` option. If there is already a docblock at the top of the file then this option will add a newline to it with the @format marker.
| Default | CLI Override | API Override |
| ------- | ----------------- | ---------------------- |
| `false` | `--insert-pragma` | `insertPragma: <bool>` |
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## Prose Wrap
_available in v1.8.2+_
By default, Prettier will wrap markdown text as-is since some services use a linebreak-sensitive renderer, e.g. GitHub comment and BitBucket. In some cases you may want to rely on editor/viewer soft wrapping instead, so this option allows you to opt out with `"never"`.
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Valid options:
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- `"always"` - Wrap prose if it exceeds the print width.
- `"never"` - Do not wrap prose.
- `"preserve"` - Wrap prose as-is. _available in v1.9.0+_
| Default | CLI Override | API Override |
| ------------ | ----------------------------------------------------------- | ----------------------------------------------------------- |
| `"preserve"` | <code>--prose-wrap <always&#124;never&#124;preserve></code> | <code>proseWrap: "<always&#124;never&#124;preserve>"</code> |