Edit

Options

Prettier ships with a handful of format options.

To learn more about Prettier’s stance on options – see the Option Philosophy.

If you change any options, it’s recommended to do it via a configuration file. This way the Prettier CLI, editor integrations and other tooling knows what options you use.

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’s printWidth option does not work the same way. It is not the hard upper allowed line length limit. It is a way to say to Prettier roughly how long you’d like lines to be. Prettier will make both shorter and longer lines, but generally strive to meet the specified printWidth.

Remember, computers are dumb. You need to explicitly tell them what to do, while humans can make their own (implicit) judgements, for example on when to break a line.

In other words, don’t try to use printWidth as if it was ESLint’s max-len – they’re not the same. max-len just says what the maximum allowed line length is, but not what the generally preferred length is – which is what printWidth specifies.

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 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:

• true - Add a semicolon at the end of every statement.
• false - Only add semicolons at the beginning of lines that may introduce ASI failures.

Default	CLI Override	API Override
true	--no-semi	semi: <bool>

Quotes

Use single quotes instead of double quotes.

Notes:

• JSX quotes ignore this option – see jsx-single-quote.
• 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 for more information.

Default	CLI Override	API Override
false	--single-quote	singleQuote: <bool>

Quote Props

Change when properties in objects are quoted.

Valid options:

• "as-needed" - Only add quotes around object properties where required.
• "consistent" - If at least one property in an object requires quotes, quote all properties.
• "preserve" - Respect the input use of quotes in object properties.

Default	CLI Override	API Override
"as-needed"	--quote-props <as-needed|consistent|preserve>	quoteProps: "<as-needed|consistent|preserve>"

Note that Prettier never unquotes numeric property names in Angular expressions, TypeScript, and Flow because the distinction between string and numeric keys is significant in these languages. See: Angular, TypeScript, Flow. Also Prettier doesn’t unquote numeric properties for Vue (see the issue about that).

JSX Quotes

Use single quotes instead of double quotes in JSX.

Default	CLI Override	API Override
false	--jsx-single-quote	jsxSingleQuote: <bool>

Trailing Commas

Default value changed from none to es5 in v2.0.0

Print trailing commas wherever possible when multi-line. (A single-line array, for example, never gets trailing commas.)

Valid options:

• "es5" - Trailing commas where valid in ES5 (objects, arrays, etc.)
• "none" - No trailing commas.
• "all" - Trailing commas wherever possible (including trailing commas in function parameter lists and calls). This requires node 8 or a modern browser that supports ES2017 or transform with babel.

Default	CLI Override	API Override
"es5"	--trailing-comma <es5|none|all>	trailingComma: "<es5|none|all>"

Bracket Spacing

Print spaces between brackets in object literals.

Valid options:

• 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:

• true - Example:

<button
  className="prettier-class"
  id="prettier-id"
  onClick={this.handleClick}>
  Click Here
</button>

• false - Example:

<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>

Arrow Function Parentheses

First available in v1.9.0, default value changed from avoid to always in v2.0.0

Include parentheses around a sole arrow function parameter.

Valid options:

• "always" - Always include parens. Example: (x) => x
• "avoid" - Omit parens when possible. Example: x => x

Default	CLI Override	API Override
"always"	--arrow-parens <always|avoid>	arrowParens: "<always|avoid>"

At first glance, avoiding parentheses may look like a better choice because of less visual noise. However, when Prettier removes parentheses, it becomes harder to add type annotations, extra arguments or default values as well as making other changes. Consistent use of parentheses provides a better developer experience when editing real codebases, which justifies the default value for the option.

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:

• 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 babel 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 babel. Almost the same applies to typescript and babel-ts. babel-ts might support JavaScript features (proposals) not yet supported by TypeScript, but it’s less permissive when it comes to invalid code and less battle-tested than the typescript parser.

Valid options:

• "babel" (via @babel/parser) Named "babylon" until v1.16.0
• "babel-flow" (same as "babel" but enables Flow parsing explicitly to avoid ambiguity) First available in v1.16.0
• "babel-ts" (similar to "typescript" but uses Babel and its TypeScript plugin) First available in v2.0.0
• "flow" (via flow-parser)
• "typescript" (via @typescript-eslint/typescript-estree) First available in v1.4.0
• "espree" (via espree) First available in v2.2.0
• "meriyah" (via meriyah) First available in v2.2.0
• "css" (via postcss-scss and postcss-less, autodetects which to use) First available in v1.7.1
• "scss" (same parsers as "css", prefers postcss-scss) First available in v1.7.1
• "less" (same parsers as "css", prefers postcss-less) First available in v1.7.1
• "json" (via @babel/parser parseExpression) First available in v1.5.0
• "json5" (same parser as "json", but outputs as json5) First available in v1.13.0
• "json-stringify" (same parser as "json", but outputs like JSON.stringify) First available in v1.13.0
• "graphql" (via graphql/language) First available in v1.5.0
• "markdown" (via remark-parse) First available in v1.8.0
• "mdx" (via remark-parse and @mdx-js/mdx) First available in v1.15.0
• "html" (via angular-html-parser) First available in 1.15.0
• "vue" (same parser as "html", but also formats vue-specific syntax) First available in 1.10.0
• "angular" (same parser as "html", but also formats angular-specific syntax via angular-estree-parser) First available in 1.15.0
• "lwc" (same parser as "html", but also formats LWC-specific syntax for unquoted template attributes) First available in 1.17.0
• "yaml" (via yaml and yaml-unist-parser) First available in 1.14.0

Custom parsers are also supported. First available in v1.5.0

Default	CLI Override	API Override
None	--parser <string> --parser ./my-parser	parser: "<string>" parser: require("./my-parser")

Note: the default value was "babylon" until v1.13.0.

File Path

Specify the file name to use to infer which parser to use.

For example, the following will use the CSS parser:

cat foo | prettier --stdin-filepath foo.css

This option is only useful in the CLI and API. It doesn’t make sense to use it in a configuration file.

Default	CLI Override	API Override
None	--stdin-filepath <string>	filepath: "<string>"

Require Pragma

First 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:

/**
 * @prettier
 */

or

/**
 * @format
 */

Default	CLI Override	API Override
false	--require-pragma	requirePragma: <bool>

Insert Pragma

First 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>

Prose Wrap

First 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".

Valid options:

• "always" - Wrap prose if it exceeds the print width.
• "never" - Do not wrap prose.
• "preserve" - Wrap prose as-is. First available in v1.9.0

Default	CLI Override	API Override
"preserve"	--prose-wrap <always|never|preserve>	proseWrap: "<always|never|preserve>"

HTML Whitespace Sensitivity

First available in v1.15.0

Specify the global whitespace sensitivity for HTML files, see whitespace-sensitive formatting for more info.

Valid options:

• "css" - Respect the default value of CSS display property.
• "strict" - Whitespaces are considered sensitive.
• "ignore" - Whitespaces are considered insensitive.

Default	CLI Override	API Override
"css"	--html-whitespace-sensitivity <css|strict|ignore>	htmlWhitespaceSensitivity: "<css|strict|ignore>"

Vue files script and style tags indentation

First available in v1.19.0

Whether or not to indent the code inside <script> and <style> tags in Vue files. Some people (like the creator of Vue) don’t indent to save an indentation level, but this might break code folding in your editor.

Valid options:

• "false" - Do not indent script and style tags in Vue files.
• "true" - Indent script and style tags in Vue files.

Default	CLI Override	API Override
false	--vue-indent-script-and-style	vueIndentScriptAndStyle: <bool>

End of Line

First available in v1.15.0, default value changed from auto to lf in v2.0.0

For historical reasons, there exist two common flavors of line endings in text files. That is \n (or LF for Line Feed) and \r\n (or CRLF for Carriage Return + Line Feed). The former is common on Linux and macOS, while the latter is prevalent on Windows. Some details explaining why it is so can be found on Wikipedia.

When people collaborate on a project from different operating systems, it becomes easy to end up with mixed line endings in a shared git repository. It is also possible for Windows users to accidentally change line endings in a previously committed file from LF to CRLF. Doing so produces a large git diff and thus makes the line-by-line history for a file (git blame) harder to explore.

If you want to make sure that your entire git repository only contains Linux-style line endings in files covered by Prettier:

1. Ensure Prettier’s endOfLine option is set to lf (this is a default value since v2.0.0)
2. Configure a pre-commit hook that will run Prettier
3. Configure Prettier to run in your CI pipeline using --check flag. If you use Travis CI, set the autocrlf option to input in .travis.yml.
4. Add * text=auto eol=lf to the repo’s .gitattributes file. You may need to ask Windows users to re-clone your repo after this change to ensure git has not converted LF to CRLF on checkout.

All modern text editors in all operating systems are able to correctly display line endings when \n (LF) is used. However, old versions of Notepad for Windows will visually squash such lines into one as they can only deal with \r\n (CRLF).

Valid options:

• "lf" – Line Feed only (\n), common on Linux and macOS as well as inside git repos
• "crlf" - Carriage Return + Line Feed characters (\r\n), common on Windows
• "cr" - Carriage Return character only (\r), used very rarely
• "auto" - Maintain existing line endings (mixed values within one file are normalised by looking at what’s used after the first line)

Default	CLI Override	API Override
"lf"	--end-of-line <lf|crlf|cr|auto>	endOfLine: "<lf|crlf|cr|auto>"

Embedded Language Formatting

First available in v2.1.0

Control whether Prettier formats quoted code embedded in the file.

When Prettier identifies cases where it looks like you've placed some code it knows how to format within a string in another file, like in a tagged template in JavaScript with a tag named html or in code blocks in Markdown, it will by default try to format that code.

Sometimes this behavior is undesirable, particularly in cases where you might not have intended the string to be interpreted as code. This option allows you to switch between the default behavior (auto) and disabling this feature entirely (off).

Valid options:

• "auto" – Format embedded code if Prettier can automatically identify it.
• "off" - Never automatically format embedded code.

Default	CLI Override	API Override
"auto"	--embedded-language-formatting=off	embeddedLanguageFormatting: "off"