Inline CSS
CSSInlines small external stylesheets to remove a render-blocking request.
Filter
inline_css
· Filter docs
A mod_pagespeed 1.15 filter. ModPageSpeed 2.0 applies it as part of one always-on pipeline, not as a separate switch.
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 mod_pagespeed 1.15 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
HTTP requests
Total bytes
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>inline_css example</title>
- <link rel="stylesheet" href="styles/all_styles.css">
+ <style>.yellow {background-color: yellow;}
+ .blue {color: blue;}
+ .big { font-size: 8em; }
+ .bold { font-weight: bold; }
+ </style>
<link rel="stylesheet" href="styles/blue.css" media="print">
<link rel="stylesheet" href="styles/bold.css" media="not decodable">
- <link rel="stylesheet" href="styles/yellow.css" media=", ,print, screen ">
- <link rel="stylesheet" href="styles/rewrite_css_images.css" media="all">
+ <style media=", ,print, screen ">.yellow {background-color: yellow;}
+ </style>
+ <style media="all">.foo {
+ background-image: url(images/BikeCrashIcn.png);
+ width: 100px;
+ height: 100px;
+ }</style>
</head>
<body>
<div class="blue yellow big bold">
Run this on your own site
This is one of 47 filters mod_pagespeed 1.15 applies in place — self-hosted on
Apache, nginx, and IIS. Install and run it: it optimizes right away and adds an
X-PageSpeed-Warn: unlicensed header until you license it. A
commercial license is required for production use.