How to Minify CSS Online

Minify CSS files instantly to reduce file size and improve page load speed. Free online CSS minifier with whitespace removal, comment stripping, and shorthand optimization.

Open CSS Minifier →

Step-by-Step Guide

1

Paste your CSS

Copy your CSS code and paste it into the input area. The tool accepts any valid CSS — stylesheets, media queries, animations, and CSS custom properties (variables).

2

Click Minify

Hit the "Minify" button. The tool removes all whitespace, comments, and unnecessary characters while preserving functionality. You will see the file size reduction percentage instantly.

3

Review the output

Check the minified result. The tool strips comments, collapses whitespace, removes trailing semicolons, and shortens color values (e.g., #ffffff → #fff) where safe.

4

Copy the minified CSS

Copy the compressed CSS to your clipboard. Use it in your production builds, CDN deployments, or inline styles. Typical savings: 20-40% file size reduction.

Try It Now — Free

No signup, no download. Runs entirely in your browser.

Open CSS Minifier

Frequently Asked Questions

What does CSS minification actually remove?
Comments, extra whitespace, newlines, last semicolons in blocks, and unnecessary zeros (0.5 → .5). It also shortens hex colors (#ffffff → #fff) and some property values.
Will minification break my CSS?
No. Minification only removes characters that browsers ignore. The CSS renders identically. If something breaks, your original CSS likely had a syntax error.
How much smaller will my CSS be?
Typically 20-40% smaller for human-written CSS. Already-minified CSS will see minimal further reduction. Large stylesheets with many comments see the biggest savings.
Related Reference

CSS Flexbox Cheat Sheet

View Cheat Sheet →

More Guides

How to Format JSON Online How to Encode & Decode Base64 How to Generate UUID Online How to Test an API Online