JavaScript Minifier

Minify JavaScript online — strip comments and whitespace to reduce bundle size.

No signup. 100% private. Processed in your browser.

Input JavaScript

Minified Output

Why Minify JavaScript?

JavaScript is usually the biggest bottleneck in web performance. It has to be downloaded, parsed, compiled, and executed — all before your page becomes interactive. Every kilobyte counts. Minification strips the parts humans need (comments, whitespace, readable names) while keeping everything the browser needs.

A typical JavaScript file shrinks 30-60% after minification. That's not just faster downloads — it's faster parsing too. V8 (Chrome's JS engine) parses minified code faster because there's less text to process. For mobile users on slow connections, the difference between 200KB and 100KB of JS can mean seconds of load time.

This tool handles comment removal, whitespace collapsing, and basic operator spacing. For production use, build tools like Terser, esbuild, or SWC provide advanced optimisations like dead code elimination, tree shaking, and variable mangling.

What Minification Removes

Element	Before	After	Savings
Comments	// Calculate total /* Multi-line */	(removed)	10-30% of file typically
Whitespace	Indentation, blank lines	Collapsed to minimum	15-25% of file
Line breaks	One statement per line	Everything on fewer lines	5-10% of file
Variable names*	calculateTotalPrice	a	Significant for large files
Dead code*	Unreachable branches	(removed)	Varies widely

What this means for you: Items marked with * require advanced AST-based minifiers (Terser, esbuild). This online tool handles comments and whitespace — the quick wins that don't risk changing behaviour. Use it for one-off jobs; use build tools for production.