Free CSS Minifier

Compress your CSS code by removing unnecessary spaces, comments, and characters to improve website performance.

Enter CSS code then click Minify button below to Minify:

Output:

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About CSS Minification

What does it mean to minify CSS?

To minify CSS is to strip out everything a browser does not need in order to apply your styles: comments, line breaks, indentation, the spaces around braces and colons, and the final semicolon in every rule. The stylesheet behaves identically and becomes considerably smaller, typically by 20 to 40 percent before compression is even applied.

It is a mechanical transformation, not a rewrite. Nothing is reordered, no rules are merged or removed, and no decisions are made about your CSS. That is precisely why it is safe to automate: the output is the same stylesheet with the whitespace taken out.

The important habit is to keep the readable source and ship the compact version. Minified CSS is close to unmaintainable by hand, so it should be a build output rather than the file you edit.

Does CSS minification still matter in 2026?

On its own the saving is modest, and smaller than people assume, because gzip and Brotli already remove much of the same redundancy. Minifying an already-compressed stylesheet usually buys a few percent rather than a transformation.

It still earns its place because it is effectively free. Every modern build tool does it by default, it costs nothing at runtime, and it applies to every visitor on every page rather than to one template.

The more useful signal is what unminified CSS in production implies. It usually means a build step is not running, or files are being edited directly on the server, and both of those tend to come with larger problems attached.

CSS best practices

Minify as part of the build rather than by hand, and keep the readable source in version control.
Publish source maps so production styles remain debuggable.
Remove unused CSS first. Minifying rules nobody applies is optimising the wrong thing.
Combine minification with server compression; they solve overlapping but not identical problems.
Inline the small amount of CSS needed for the top of the page and defer the rest.
Never block stylesheets in robots.txt.

Common mistakes

Editing the minified file directly, so the next build silently reverts the change.
Shipping several large stylesheets when most of the rules are never used on the page.
Assuming minification replaces compression, when the two are complementary.
Leaving development builds in production after a deployment process changes.
Minifying by hand and introducing a syntax error that removes a whole block of styling.

Using the CSS minifier

Paste your stylesheet into the input and the tool returns the minified version to copy out. It is a one-off utility, useful for a single file, a snippet you have been handed, or checking how much a stylesheet stands to save before wiring minification into a build.

For anything ongoing, minify CSS as part of your build pipeline instead. Doing it manually works once and then quietly stops happening, which is how sites end up serving a stylesheet that was minified two redesigns ago.

Where to go next

Stylesheets are one part of what a page has to download. Minify the other two with the JavaScript minifier and the HTML minifier, check whether your live assets are already minified with the minification checker, and see what the total weight is costing you with the page size and website speed tools.

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