Google have always been obsessive about speed and have rightly prided themselves as the fastest search engine available. This has surely been one of the contributing factors to their success. Now Google is trying to encourage other websites to follow their lead.
In his 2009 State of the Index presentation, Matt Cutts confirmed that Google is looking at ways to include site speed as one of the factors that affects ranking positions during 2010.
“We don’t currently use page speed as factor in search results… there are people at Google who definitely want to and a lot of people at Google are working on it.”
All things the same, faster websites make for a better user experience and Google want to improve the quality of their results by prioritising the pages fastest pages and penalising the slowest.
What is Fast?
Useit.com give a nice summary on the effect of response time for an interactive system.
The best way to think of this is to imagine a curved line showing load times against bounce rate. The longer the load time, the greater the percentage of people who will bounce back to Google.
There is no specific point at which a site becomes fast or slow. Google searches are almost always completed and returned in less than a second which is an astonishing achievement that few can match.
A new feature in Webmaster Tools Labs called Site performance gives us a clue. You can view the average load time of pages for your site over time. The data is collected from real users with the Google Toolbar installed so it’s a reasonably accurate model of real world performance. The graph shows a pink section which is clearl marked as SLOW. They determine this cutoff pointe explain that they consider the top 20% of fastest sites to be fast.
Site Performance vs. Page Performance
The figures provided in Webmaster Tools are an average of all your pages combined which could suggest that the overall site performance will affect the rankings of all pages on your site, not just the slow ones.
At other times, Matt Cutts referred to Page load times affecting a pages ranking which would suggest that each individual page is considered independently. Perhaps it could be a combination of the two. Maybe this is one of the aspects currently under consideration at Google. The safest strategy is to assume that it’s important to maintain good site performance on individual pages and across the entire site.
How to measure site performance
The most crude form of performance measurement is to look at the size of your HTML pages. It’s quite easy to identify large HTML pages which, all things the same, are likely to load slower. Any pages that have over 100KB of HTML are worth investigating to see if they can be optimised or split into smaller pages where it makes sense.
Firefox developers will already be familar with the rather splendid Firebug plugin which shows you gory details of all the HTTP requests that go into a single page load.
Chrome has a similar tool available as part of the Developer Tools which can be activated by pressing CTRL + SHIFT + J and selecting the Timeline tab.
This is a great way to check individual pages for free. If your site is important, you should consider implementing a monitoring service that checks key pages periodically and alerts you to performance issues as they arise.
How to improve site performance
Once you have some idea of your site performance, you can start working on optimising your pages.
Google have also included a rather handy practical guide to optimising your site performance called Web Performance Best Practices but it usually includes the following exercises.
It’s best to start looking at common page elements which are affecting all pages across your site before looking at individual pages. You should focus on your most important pages first and your home page is almost certainly worthy of a focused effort to improve the speed.
Here is a simple strategy to follow to ensure that are not adversely affected.