What it is
The CSS and JS Minifier strips everything a browser does not need out of a stylesheet or a script: comments, line breaks, indentation and redundant spaces.
What minifying actually buys you
Smaller files, which means less to download and a page that starts rendering sooner. On a typical stylesheet the saving is 20 to 40 percent before compression, and more once the server gzips it on top.
It matters most on mobile connections and on repeat-heavy files. It matters least on a small file that was already tiny.
How to use it
- Paste the CSS or JavaScript.
- Minify.
- Copy the result into your build or straight into the file you serve.
The rules of doing this safely
Never minify over your only copy. Minified code is unreadable and there is no reliable way back. Keep the source, minify on output.
Test after minifying. For CSS the risk is low. For JavaScript it is real: code that relies on automatic semicolon insertion can break when line breaks disappear, and that failure often shows up only in one browser or one code path.
Do it last. Minify after everything else in your build, never before, or you will be debugging generated code.
If your project already has a build step, it almost certainly minifies for you. This tool is for the cases that do not: a single file, a snippet, a page you maintain by hand, or a quick check of how much a file would actually save.
Nothing is uploaded
The whole operation runs inside your browser. Your file is never sent to a server, never stored and never seen by anyone else. No queue, no daily cap and no account.