Bad news for internet slowpokes. Google said it will now factor in how fast a web site loads into its search rankings.

Google said that fewer than 1 percent of search queries will be affected by the change, and it only applies for visitors searching in English. The search engine considers more than 200 different variables in its rankings and changes its algorithms constantly; it said it launched this change a few weeks ago after “rigorous testing.”

Google Fellow Amit Singhal and principal engineer Matt Cutts wrote today:

Speeding up websites is important — not just to site owners, but to all Internet users. Faster sites create happy users and we’ve seen in our internal studies that when a site responds slowly, visitors spend less time there. But faster sites don’t just improve user experience; recent data shows that improving site speed also reduces operating costs. Like us, our users place a lot of value in speed — that’s why we’ve decided to take site speed into account in our search rankings.

Cutts had hinted about such a change as early as last year. The search engine has long prized speed. Experiments last year showed that slowing down the search results page by 100 to 400 milliseconds meant 0.2 to 0.6 percent fewer searches. The longer Google users were exposed to the experiment the more they decreased their searches.