JS Beautifier Online — Free JavaScript Formatter

When you need to inspect a third-party CDN script, debug a production bundle in the browser, or audit a library before shipping it, a beautifier is the first stop. The OpenFormatter implementation handles arrow functions, async/await, template literals, optional chaining, and every modern JS feature — because it operates on braces and string boundaries, not on a specific language version.

How to beautify JavaScript — 4 steps

1. Paste minified JS. A webpack bundle, a CDN script, a single-line snippet from your build output. Click Load Sample to try.
2. Click Beautify. The tool inserts line breaks and indentation client-side. Strings, regexes, and template literals are preserved exactly.
3. Read the output. One statement per line, control flow visible at a glance, nested blocks correctly indented.
4. Copy or save. Use Copy to grab the result, or save to a .js file for further editing in your IDE.

Sample transformation

const f=(a,b)=>{if(a>b){return a}return b};const r=f(3,7);console.log(r);

const f = (a, b) => {
  if (a > b) {
    return a
  }
  return b
};
const r = f(3, 7);
console.log(r);

Every brace gets its own line, semicolons end statements, and indentation reflects nesting depth — readable code from a single dense line.

Common use cases

• check_circleBeautifying a webpack/rollup/esbuild production bundle for debugging
• check_circleReading minified JavaScript from a CDN before adding it to your site
• check_circleAuditing third-party scripts (analytics, ads, A/B testing) for unwanted behaviour
• check_circleRestoring formatting on JS recovered from a browser DevTools sources panel
• check_circleInspecting bookmarklet code that was deliberately compressed to fit a URL
• check_circleReading JS embedded in a one-line <script> tag from someone else's page
• check_circleCleaning up JS exported from a no-code tool that strips formatting
• check_circleEducational use — showing students what minified code expands to

Beautifier vs Prettier: which to use

Prettier is the right tool for source code: it parses with a real AST, applies opinionated style rules (line wrapping, trailing commas, quote normalisation), and produces canonical formatting your team can enforce in CI. A beautifier is the right tool for code you did not write — minified bundles, third-party scripts, or production debugging — where you just need readable formatting fast, without configuring a parser. Use Prettier for your source; use this beautifier for everything else.