ToolNestFree Online CSS Minifier
Quick answer: Shrink your stylesheets without touching your design. Our free CSS minifier strips comments and whitespace, shortens hex colors like #ffffff to #fff, and drops redundant units like 0px — while protecting quoted strings and keeping required spaces inside calc() so nothing breaks. Paste, minify, then copy or download the result. No signup, everything runs in your browser.
Shrink your stylesheets without touching your design. Our free CSS minifier strips comments and whitespace, shortens hex colors like #ffffff to #fff, and drops redundant units like 0px — while protecting quoted strings and keeping required spaces inside calc() so nothing breaks. Paste, minify, then copy or download the result. No signup, everything runs in your browser.
✓ Free forever · ✓ No signup · ✓ Runs in your browser — your data never leaves your device.
How to Use the CSS Minifier
- Paste your CSS into the input box (or click 'Try sample CSS' to see it in action).
- Click 'Minify CSS' — comments and whitespace are removed instantly, hex colors shortened, zero units dropped.
- Check the stats line: it shows the original size, the minified size, and the percentage saved.
- Click 'Copy Minified CSS' or 'Download .min.css' and use it in your production page.
- Keep your original file for editing — re-minify it any time you make changes.
Why Use Our CSS Minifier?
- String-safe — quoted strings are protected first, so
content: "/* */"survives intact. - calc() aware — required spaces around operators inside
calc()are preserved. - Hex shortening —
#aabbccbecomes#abc; 8-digit alpha hexes are left alone. - Zero-unit cleanup —
0px,0em,0vhbecome0; keyframe0%selectors are never touched. - Instant stats + download — see bytes saved and grab the file with one click.
Common Use Cases
- Production stylesheets: Minify the final CSS before deploying so visitors download the smallest possible file.
- WordPress theme tweaks: Shrink CSS pasted into the Customizer's 'Additional CSS' box so it loads faster on every page.
- Inlining critical CSS: Minified CSS is what you paste into <style> tags for above-the-fold critical-CSS optimizations.
- Sharing snippets: One-line minified CSS is easy to paste into forums, gists, and chat without formatting noise.
- Auditing bloat: Paste a stylesheet and compare before/after sizes — a tiny saving means your CSS was already tight.
CSS Minifier vs Alternatives
- cssminifier.com: A dedicated minifier with a similar job; ad-heavy pages and your CSS leaves the browser. Ours runs 100% locally with no ads or signup.
- Build tools (PostCSS/cssnano, Vite): The right choice inside a build pipeline — automatic on every deploy. Ours is for quick one-offs, legacy projects, and people without a build step.
- VS Code minify extensions: Convenient if you live in an editor; ours works from any device with a browser, nothing to install.
- Online 'all-in-one' tool sites: Often bundle a minifier with dozens of unrelated tools and aggressive ads. Nest of Tools does one thing per page, privately in your browser.
If you already run a build pipeline, let it minify automatically — it's the zero-effort option. For everything else — a quick paste, a legacy site, a Chromebook — this page minifies your CSS in one click without uploading it anywhere.
Frequently Asked Questions
What does a CSS minifier do?
#ffffff becomes #fff, 0px becomes 0, and trailing semicolons disappear. The result is one line that renders pixel-identically to the original.How much smaller will my CSS get?
Will minifying break my CSS?
content: "→") are protected, required spaces inside calc(100% - 20px) are preserved, and keyframe 0% selectors are never altered. Still, always keep the original file for editing.