JavaScript Formatter

Runs entirely in your browser

Beautify and indent JavaScript directly in your browser. This only rewrites text — it never executes your code.

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What is JavaScript Formatter?

JavaScript Formatter re-indents JavaScript code based on braces and statement boundaries, making nested functions, conditionals and loops easy to read. It never runs your code — only the text layout changes.

How to use JavaScript Formatter

  1. Paste your JavaScript into the Input box.
  2. Choose an indent size.
  3. Click Format, then copy the result.

Features

  • Indents nested blocks based on braces.
  • Correctly recognizes strings, template literals and regex literals.
  • Keeps for-loop headers (e.g. for (let i = 0; i < n; i++)) on one line.
  • Never uses eval — your code is never executed.
  • 100% client-side — your code never leaves your browser.

Example

This condensed function:

function greet(name){if(name){return `Hello, ${name}!`}else{return "Hello!"}}

becomes:

function greet(name) {
  if (name) {
    return `Hello, ${name}!`
  } else {
    return "Hello!"
  }
}

Tips for using JavaScript Formatter

  • else is appended to the same line as the preceding closing brace — } else {, as shown in the Example above — matching the common "one true brace style" rather than putting else on its own line.
  • The formatter never inserts semicolons that weren't already in your source. Notice the Example input has none, and the formatted output doesn't gain any either — only spacing and line breaks change.
  • Deciding whether a / starts a regex literal or means division is based on the token immediately before it — after an operator, (, or a keyword like return, a / is treated as a regex; after an identifier or ), it's division. This heuristic covers the vast majority of real code but isn't a full grammar analysis.
  • Template literals are scanned with awareness of nested ${...} expressions, including ones containing their own quotes or backticks, so a template literal inside another expression won't be mistaken for the end of a code block.

Is JavaScript Formatter safe?

Yes. The regex-vs-division heuristic and brace-based indentation described in the Tips above run locally in your browser, and the code you paste is never passed through eval, executed, or uploaded to our servers.

Frequently Asked Questions

Does this execute my code?

No. This tool never uses eval or runs your code — it only rewrites the text for readability.

Does this handle template literals and regular expressions?

Yes. Template literals (including ${...} expressions) and regex literals are recognized and left untouched, rather than being misread as strings or division.

Is this a full JavaScript parser?

No. It re-indents code based on braces, parentheses and statement boundaries — good for typical code, but it isn't a full AST-based formatter like Prettier, so unusual syntax may not format perfectly.

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