Google has released mod_pagespeed, a module for Apache HTTPD to speed up serving web pages. It claims to double speed by adding HTTP cache friendly messages without having to make changes to the web applications that are hosted in it.
In the blog post announcement, they describe some of the optimisations, including minimising round-trip times, optimising caching and minimising payload size. The module is being rolled out across GoDaddy as well as the content delivery network Contendo.
The speed optimisations come from a number of filters, which are individually enabled:
- Minifying HTML CSS and JavaScript on the fly, and serving back those files for subsequent requests (including removing comments, whitepsace and unnecessary quoting)
- Combining multiple CSS files into a single CSS delivery component
- Merging CSS into HEAD of an HTML file
- Adding caching headers, such as
Cache-Control, to content that is served without caching - Inlining small images into base64 using the
data:URL scheme - Scaling down large images to provide a 1-1 mapping to an image's specified size in the HTML document
Google have a YouTube video showing the speed difference:
What do you think of the mod_pagespeed extension? Will you be using it?