JavaScript Minifier
Free JavaScript minifier that runs browser-local. Minify JS by removing comments and whitespace. No upload, no account, no code execution.
Runs locally in your browser. Your input is not uploaded to DevToolMate servers.
Minify only
Minifies JavaScript source as text only. This is not a full AST optimizer and never runs the code.
Developer Quick Tips
- Minify JavaScript browser-local by pasting or opening .js, .mjs, or .cjs files; no upload, no account, no execution.
- Remove // and /* */ comments, collapse whitespace, preserve string and template literals in one click.
- Download minified output as minified.js; compare file size reduction; use Ctrl or Cmd + Enter to minify.
- Text-based minification only: no AST optimization, variable renaming, or tree-shaking like Terser or esbuild.
- Your code stays on your device. This free tool never uploads, executes, or stores your JavaScript after the tab closes.
Frequently asked questions
Can I minify JavaScript online without uploading my code?
Yes. This online minifier runs entirely in your browser. Your code never leaves your device and is never uploaded to DevToolMate servers or external services.
Does this online JavaScript minifier execute my code?
No. This tool processes JavaScript as text only. Your code is never executed, evaluated, or run. It is safe to minify untrusted or sensitive code.
What does this online minifier remove from JavaScript?
It removes line comments (//), block comments (/* */), and collapses extra whitespace and line breaks. String literals, template literals, and all code logic are preserved intact.
Is this free online JavaScript minifier really free?
Yes. This online minifier is completely free with no account, login, or payment required. Minify as many files as you need.
How does this online minifier compare to Terser or esbuild?
This tool minifies JavaScript as text and does not perform AST-level dead-code elimination, variable renaming, or tree-shaking. Use it for quick online compression; use production bundlers for full optimization.
Can I minify .mjs and .cjs files with this online minifier?
Yes. This online minifier supports .js, .mjs, and .cjs files. Paste or open any of these file types to compress them in your browser.
What is the difference between minification and uglification?
Minification removes comments and whitespace; uglification (like Uglify or Terser) also renames variables and performs dead-code elimination. This online minifier removes comments and whitespace only, making it faster but less aggressive than full uglification.
Related tools
- JavaScript Formatter: Format JavaScript online in your browser with custom indentation. Free, no upload, no account. Pretty-print minified JS as text only - code never executed or stored.