Minify CSS
CSSStrips whitespace and comments, then rewrites CSS to the smallest equivalent form.
Filter
rewrite_css
· Filter docs
A module filter.
Both frames render identically — that's the goal. The win is in the bytes and requests
below, not the look. They're served live by the mod_pagespeed module on
demo-httpd-1.1.modpagespeed.com; the optimized frame
applies only this filter. Right after a cache purge it may briefly match the original while
the worker rewrites it — reload to see the result.
Measured impact
Total bytes
HTML size
What changed in the source
The page's HTML, before and after this filter. Red lines are removed, green lines are added.
<html>
<head>
<title>rewrite_css example</title>
- <style type='text/css'>
- #iddy, #anotherId {
- /* This comment will be stripped.*/
- border: solid 1px #cccccc;
- padding: 1.2em;
- float: left;
- color:WindowText;
- }
- div.classy span, div.classy img {
- display: block;
- border: none !important;
- background: none !important;
- }
- </style>
- <link rel="stylesheet" type="text/css" href="styles/yellow.css">
+ <style type='text/css'>#iddy,#anotherId{border:solid 1px #ccc;padding:1.2em;float:left;color:WindowText}div.classy span,div.classy img{display:block;border:none!important;background:none!important}</style>
+ <link rel="stylesheet" type="text/css" href="styles/A.yellow.css.pagespeed.cf.KM5K8SbHQL.css">
</head>
<body>
<div class="blue yellow big bold">
Run this on your own site
This is one of 49 filters the mod_pagespeed module applies in place — self-hosted on Apache, nginx, and IIS. Install and run it: it optimizes right away and adds an the optimized response headers shown above. Open source under the Apache License 2.0 — free in development and in production.