Google has just announced a content delivery network (CDN) called Page Speed Service. Page Speed Service basically improves web page latency by changing the resources on that web page to implement web performance best practices such as 17 rules of webpage speed optimisation. Each change that Page Speed Service makes corresponds to a rewriter. These rewriters are applied in a pre-defined order on any resource being served by the service. Some basic optimizing rewriters are applied by default by Page Speed Service (e.g. gzip, HTML cleanup etc.) while other can be enabled and disabled in the Rewriter Settings section of the Google APIs Console, see below.

According to Google, “to use the service, you need to sign up and point your site’s DNS entry to Google. Page Speed Service fetches content from your servers, rewrites your pages by applying web performance best practices, and serves them to end users via Google’s servers across the globe. Your users will continue to access your site just as they did before, only with faster load times”. Current benchmarks indicate that Gooogle Page Speed Service boosts page speed anything between 25- to 60-percent after you allow it to prefetch your site.

The extent of speed up depends on a variety of factors such as content on your pages, browser, geographic location of access, bandwidth, etc. You can run tests to measure the speed up of your site in a few minutes. At this time, Page Speed Service is being offered to a limited set of webmasters free of charge. Pricing will be competitive and details will be made available later.

Here is a preview of the console:

According to Google’s own tests, hey have seen speed improvements of 25% to 60% on several sites which means the service is going to be very useful for webmasters who are struggling to improve their website’s performance. However, this service does come with a few downsides such as:

Drawback of Google PSS

  • Page Speed Service currently does not support https traffic
  • Files greater than 50MB in size are currently not supported by Page Speed Service.
  • Flash, streaming audio and video content are not currently supported
  • POST requests of size greater than 2MB are currently not supported
  • Page Speed Service does not support reference domains that have only an IPv6 address.

From an SEO perspective, using Google Page Speed Service might have adverse effect on your image rankings because your images will have to be reindexed from a different URL.

How does Page Speed Service measure page load?

The PSS rewriter injects two small blocks of CSI (Client Side Instrumentation) javascript into every HTML page of your website. These blocks measure the time the client spends loading and rendering the page, and report that measurement back to Google. You can then access the load time metrics for your site on the PSS dashboard. By default the writer is enabled across the entire website however you can “blacklist” certain pages if you wanted to exclude them.

Want to demo Google PSS?

You can demo PSS Rewriters here and if you are the curious type just like myself then you will probably want to double check Google’s claim using their sister speed checking service – Google Page Speed Online. My tests show that before using Google PSS Page Speed Online gives each of the aforementioned demos 91 out of 100. However if you test the “after” version then you will get a straight 99 score like the one below which is fantastic!