Urchin, which is based in San Diego, is a software company serving Web site owners and marketers, helping them to understand how customers use Web sites and track marketing performance.
Urchin's software is available as a hosted service, a software product and through large Web hosting providers, said Google, which is based in Mountain View, Calif. These products are used by thousands of popular sites on the Internet.
Google said it planned to make these tools available to Web site owners and marketers to enable them to increase their advertising return on investment and make their Web sites more effective.
The deal is expected to be completed before the end of April.