JS / CSS / HTML Minifier
Minify JavaScript, CSS, and HTML to reduce file size and load times. See exact byte savings instantly. Powered by Terser, clean-css, and html-minifier-terser — everything runs in your browser. Nothing is uploaded.
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Minified output will appear here
Frequently Asked Questions
- How much can minification reduce file size?
- Typically 30–70% for JavaScript and CSS. HTML varies more depending on whitespace and comments. The tool shows the exact byte savings for your specific code after every keystroke.
- Does JavaScript minification break my code?
- No. Terser (the industry standard used by webpack, Vite, and esbuild) only removes whitespace and comments, and safely renames variables. The logic is preserved exactly. You can disable mangling if you need readable identifiers in the output.
- What is variable mangling?
- Mangling renames long variable names to short ones (e.g. 'myVariable' → 'a') to reduce file size further. It is safe for bundled code but should be disabled if you need the output to be human-readable or interop with external APIs by name.
- Is my code sent to any server?
- No — all minification runs entirely in your browser using Terser, clean-css, and html-minifier-terser loaded from esm.sh CDN. Your code never leaves your device.
- Can I minify inline JavaScript and CSS inside HTML?
- Yes. Enable 'Minify inline JS' and 'Minify inline CSS' in the HTML options panel. Terser and clean-css will be applied to script and style blocks embedded inside your HTML.
- Does it work on mobile?
- Yes, the tool works on all modern browsers including mobile. The split-panel layout stacks vertically on smaller screens for easy use.