It’s official: Google, the search engine giant, has now added site speed as a factor in improving page rankings. Site speed measures how quickly a web page loads based on certain requests.

Matt Cutts said last year that there was “strong lobbying” inside Google to account for site speed as a new ranking factor. While this was a great idea last year, this year it’s a reality.

Google has noted that “faster  sites create happy users” and that visitors have spent less time on sites that take too long to load. A recent study (http://searchengineland.com/google-now-counts-site-speed-as-ranking-factor-39708) has shown that users will leave a site when the delay is over half a second.

So, how does Google measure site speed? Google Fellow Amit Singhal mentions that there are two main ways how Google will measure page speed:

  1. How fast a web page responds to Googlebot
  2. Load time as measured by the Google Toolbar

Last December, Google added under the “Labs” section of Webmaster Tools a “page speed report.” That would show how fast your site loaded as well as some suggestions on improving it.

So, what tools should SEO experts use for site speed? Google’s blog rankings (http://googlewebmastercentral.blogspot.com/2010/04/using-site-speed-in-web-search-ranking.html) has mentioned the following:

While Google ‘s algorithm has over 200 factors to determine page ranking, and Google is unusually publicly announcing a new page ranking factor, Matt Cutts warns not to overestimate the impact of page speed on website rankings.

“Quality should still be the first and foremost concern,” Cutts states. “This change affects outliers; we estimate that fewer than 1% of queries will be impacted. If you’re the best resource, you’ll probably still come up.”

Singhal says the focus remains on improving the user experience on Google.com, and the company can’t do that if it gets the relevance of search results wrong. “We want to return faster sites,” he says, “but not at the expense of relevance.”

While only 1% of sites right now are affected by the site speed factor and that it’s only factored in at this time for English-language websites, this number will eventually go up.