CSS & JS Minifier
Minify CSS and JavaScript online — strip comments and whitespace safely, see bytes saved, then copy or download the compressed code.
About the CSS & JS Minifier
This minifier compresses CSS and JavaScript right in your browser. The CSS mode removes comments, collapses whitespace and trims spaces around braces, colons and commas using conservative transformations that never change what the styles do — selectors, values and media queries come out byte-for-byte equivalent.
The JavaScript mode is a deliberately basic minifier: it strips // line comments and /* block */ comments with a character-level scanner that leaves string and template literals untouched, then removes trailing spaces and collapses blank lines. It won't rename variables or restructure code like a build-tool minifier, which also means it can't break anything subtle.
After minifying you see the size before and after and the percentage saved, with one-click copy or a direct .css / .js download. Handy for quick edits to legacy sites, email-friendly snippets and CMS style fields.
How to Use the CSS & JS Minifier
- 1Choose the CSS or JavaScript tab.
- 2Paste your code into the input box.
- 3Click Minify and check the bytes saved.
- 4Copy the result or download it as a file.
Frequently Asked Questions
How much smaller does minified CSS get?
Typically 15–40% smaller, depending on how heavily the original is commented and indented. Hand-written CSS with generous comments compresses the most. Remember that gzip/brotli on your server compounds the saving — minified + gzipped is the combination virtually every production site ships.
Is it safe to minify my code with this tool — can it break anything?
The CSS transformations are conservative: only comments and insignificant whitespace are touched, so the output behaves identically. The JavaScript mode is intentionally basic — it removes comments and blank lines but never renames or restructures code, and its character scanner protects strings and template literals. As always, test the output before deploying, especially unusual code containing regex literals with double slashes.
What is the difference between this and a build-tool minifier like Terser?
Terser, esbuild and cssnano perform aggressive optimizations — renaming variables, dropping dead code, merging rules — achieving greater compression at the cost of a build pipeline. This tool is for the times you don't have one: pasting a snippet into a CMS, shrinking a legacy file or cleaning code quickly. For application bundles, use a build tool.
Should I keep the unminified original?
Absolutely. Minification is one-way — comments are gone forever and formatting must be reconstructed by a beautifier. Treat the readable version as your source of truth in version control and generate the minified copy from it whenever you deploy, whether with this tool or a build step.
Is my code uploaded anywhere when I minify it?
No. All processing happens in JavaScript inside your browser — the code never touches a server, which makes the tool safe for proprietary source and works even offline once the page has loaded.