Paste your stylesheet, pick an action and get clean output in one click. Use it to minify CSS before you deploy, beautify a squashed stylesheet so you can read it, or unminify a file you inherited. Everything runs in your browser, so your code is never uploaded.
What is CSS minification?
CSS minification removes everything a browser does not need to render your styles: comments, line breaks, extra spaces, and the last semicolon in a rule. It can also shorten values, such as #ffffff to #fff or 0.5em to .5em. The result behaves exactly the same but weighs less, so pages download faster. Think of it as a CSS compressor that never changes how your design looks.
How to minify a CSS file online
- Paste your CSS into the input box, or enter a URL to fetch a stylesheet.
- Choose Minify.
- Copy the output or download it as
style.min.css. - Upload the minified file and point your theme or plugin at it.
Always keep your original, readable file as the source of truth and edit that one. Regenerate the minified copy whenever you change it. On WordPress sites, a caching or optimization plugin can do this automatically, but a manual pass is handy for custom theme files and quick checks.
How to beautify and unminify CSS
A CSS beautifier (also called a CSS formatter) adds indentation and line breaks so each selector and property sits on its own line. Paste any minified file, choose Beautify or Unminify, set your indent size, and the tool restores a readable layout. This is the quickest way to inspect a third-party stylesheet, debug a theme, or tidy code before a code review.
Note that unminifying restores formatting, not comments or original variable names that were removed during minification. If you need those, go back to the source file.
Why minifying CSS matters
CSS is render-blocking: the browser waits for it before painting the page. Smaller files mean quicker first paint and better Core Web Vitals, which in turn help user experience and search visibility. Savings vary by file; heavily commented or loosely formatted stylesheets shrink the most. Pair minification with server compression such as Gzip or Brotli, and read Google’s guide to minifying CSS for the full picture. If you also ship HTML templates, run them through our HTML minifier and beautifier for the same benefit.
Syntax checker and error finder
Beautifying a stylesheet is also the easiest way to spot problems: missing semicolons, unclosed braces, or a misspelled property stand out once the code is properly indented. For a formal check against the specification, run your file through the W3C CSS Validator. Browser DevTools will also flag invalid properties in the Styles panel.
Free CSS generators and resources
Once your code is clean, these free generators save time on common styling jobs. Paste the generated CSS into the tool above to minify it for production.
| Need | Resource | Best for |
|---|---|---|
| Gradient generator | CSS Gradient | Linear and radial backgrounds |
| Box shadow and border radius | CSSmatic | Cards, buttons, soft corners |
| Animation generator | Animista | Ready-made keyframe animations |
| Grid generator | CSS Grid Generator | Page and gallery layouts |
| Flexbox reference | CSS-Tricks Flexbox guide | Alignment and responsive rows |
| Color palette generator | Coolors | Brand and UI palettes |
| Properties and selectors reference | MDN CSS docs | Tutorials, examples, browser support |
Prefer a ready-made foundation instead of writing everything by hand? Compare options in our guide to the best CSS frameworks.
Quick CSS cheat sheet
- Selectors:
.class,#id,a:hover,ul > li - Layout:
display:flex,display:grid,gap,justify-content - Responsive:
@media (min-width: 768px) { ... } - Modern features: custom properties
var(--brand),clamp(),aspect-ratio, container queries - Tip: keep a readable source file and ship only the minified build.
FAQ
Is this CSS minifier free?
Yes. It is free, needs no signup, and processes code locally in your browser.
Will minifying break my design?
Standard minification only removes unneeded characters, so rendering should not change. Test on a staging site before deploying, especially if your CSS relies on unusual hacks.
Can I unminify any CSS file?
Yes. Unminify restores indentation and line breaks, though removed comments cannot be recovered.
What is the difference between a CSS minifier and a compressor?
People use the terms interchangeably. Minification edits the code itself; Gzip or Brotli compression happens at the server level and works on top of it.