Over the last few weeks, we've been busy testing Google's mod_pagespeed technology with our cPanel servers. We now announce that all cPanel servers and websites are using mod_pagespeed.
What is mod_pagespeed?
mod_pagespeed is a module for Apache web server, developed by Google to help reduce page loading times. As you may already know, Google estimates page loading times and adjusts the ranking of that page accordingly. What this means is that faster websites will appear higher in the search results and slower websites will sink down.
How mod_pagespeed speeds up websites?
mod_pagespeed applies various technologies, such as
- CSS and JS files aggregation. Aggregation allows to significantly reduce the number of requests to load multiple CSS and JS files typically found in any modern CMS or shopping cart. Aggregation means that instead of, let's say, 20 CSS and 20 JS files, they are combined into 4 CSS and 4 JS files. mod_pagespeed is smart enough to determine the most effective way to combine those files and exclude files that cannot be combined (e.g. files with errors in them).
- Image resampling and recompression. We often observe that websites include a large image (several megabytes) displayed as a smaller image. For example, CSS or forcefully added image dimensions visually reduce the image served by the web page, but the image size remains large. This slows down page loading time and affects user experience. mod_pagespeed identifies such image and recompresses it to match the actual dimensions. This technique sometimes results in several megabyte page size reduction and loading speeds reduce dramatically.
How to change the way mod_pagespeed works for your site?
Most of operations on changing the way mod_pagespeed works for your website can be implemented inside .htaccess file. We posted some examples how to disable (or enable) specific filters, also advising how to disable mod_pagespeed for your website. Check this article for some examples.
How much faster my website may be with mod_pagespeed?
It is hard to guarantee any specific speed improvements, but in majority of cases there is noticeable improvements in page loading speeds.
Here are some examples
We applied mod_pagespeed to our own website (Drupal 7) and the client area (running WHMCS), the speed improvement was about 100%. According to http://www.webpagetest.org and https://developers.google.com/speed/pagespeed/insights/ our web site is now loading 3.5 seconds in average (for the home page), comparing to around 7-8 second before the optimisation.
One of our Managed Secure VPS Hosting customers, running WordPress and online shop. Requested mod_pagespeed optimisation, with the outstanding outcome. Pages loading time improved over 2.5 times in average. This website displays a large number of image content for their products variety.