Format JavaScript

Format JavaScript with consistent indentation, spacing, and line breaks.

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ToolJavaScript Formatter

Input

Output

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Put this on your own site

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AccentBackground

Pick a dark background and the text and panels follow it, so the frame stays readable on a dark page.

How it works

Tokens are spaced and indented around braces, brackets, semicolons, and nesting while strings and comments remain opaque. Layout changes do not intentionally change program semantics.

Two-space indentation and 80-column wrapping are readable defaults.
Quote and semicolon styles remain configurable.

Worked example

Format minified JavaScript

Add indentation to compressed JavaScript code

Input

											function greet(name){if(name){console.log('Hello '+name);}else{console.log('Hello World');}}

Output

												function greet(name) {
  if(name) {
    console.log('Hello '+name);
  }
  else {
    console.log('Hello World');
  }
}

When to use this

Pre-commit hooks, code reviews, and readable generated bundles format JavaScript.

Edge cases

Template-literal braces are not block syntax.
Automatic semicolon insertion makes some line breaks significant.
Regex literals contain punctuation that is not an operator.

References

ECMAScript specification