JavaScript Minifier/Formatter
Minify JavaScript to reduce file size for production, or format messy code for readability. Shows size reduction percentage. All processing is local — your code is never sent to any server.
About JS Minifier
Minification removes whitespace, comments, and shortens variable names to reduce file size for production. Formatting does the reverse — adds indentation and line breaks for readable code.
🔒 All processing happens locally in your browser.
All processing happens locally in your browser — nothing is stored or sent to any server.
How to Use This JS Minifier/Formatter
- Paste your JavaScript code into the input field.
- Click Format to get readable, indented code.
- Click Minify to compress code and reduce file size.
- The stats bar shows character count, line count, and reduction percentage.
- Use Copy to copy the result, or Load Sample to try it.
About JavaScript Minification
JavaScript minification is a core optimization technique used by virtually every production web application. By removing comments, collapsing whitespace, and producing a single-line output, minified JavaScript files load faster and consume less bandwidth. This directly improves page load times and Core Web Vitals scores.
Modern build tools like webpack, Vite, and Rollup perform minification as part of their production builds (typically using Terser or esbuild). This tool gives you the same capability without any build setup — paste code and get minified output instantly.
This tool runs 100% in your browser. Your JavaScript code is never uploaded to any server, making it safe for proprietary or sensitive code.
Frequently Asked Questions
What is JavaScript minification? ▼
JavaScript minification is the process of removing all unnecessary characters from code — whitespace, newlines, comments — without changing its functionality. The result is a significantly smaller file that loads faster in browsers. This is standard practice for production deployments.
What is the difference between formatting and minification? ▼
<strong>Formatting</strong> (also called beautifying or pretty-printing) adds indentation, line breaks, and spacing to make code human-readable. <strong>Minification</strong> does the opposite — it removes everything possible to make the file as small as possible for production. Both preserve the code's behavior.
Does minification change how my code works? ▼
Proper minification should not change your code's functionality. This tool removes comments and whitespace only — it does not rename variables or perform other transformations that could break code. Always test your minified code in a browser before deploying.
How much smaller will my code get? ▼
It depends on the ratio of code to comments and whitespace. Typical minification reduces file size by 20-40%. Code with many comments and loose formatting will see the biggest reductions. The tool shows you the exact reduction percentage.
Is my JavaScript code sent to a server? ▼
No. All processing — both formatting and minification — happens entirely in your browser using JavaScript. Your code never leaves your device.
Should I minify ES modules and modern JavaScript? ▼
Yes — modern bundlers like Vite, esbuild, and Rollup all minify ES modules in their production builds. The output remains valid JavaScript that any modern browser can parse. The bigger wins come from tree-shaking and code-splitting alongside minification, but those require a bundler — this tool handles the minification step alone for ad-hoc scripts.
Can I use this output in production? ▼
For small standalone scripts, yes — paste the minified output into your HTML or CDN bucket. For larger applications, prefer a real build pipeline (Vite, esbuild, webpack) so you also get source maps, tree-shaking, and dependency-graph minification, which together produce smaller bundles than this tool can.
What about source maps? ▼
This tool does not generate source maps. Source maps are usually produced by build tools (Terser, esbuild) and let browsers map minified code back to the original source for debugging. If you need debugging in production, use a build pipeline that emits source maps.