Zillow's website was launched on February 8, 2006, and included a home-valuation tool that anyone could use. Other features at the time included information about home sale history and charts and graphs comparing home value appreciation with other towns or states. The site crashed on the morning it launched because its servers were unable to handle the volume of traffic.

In July 2006, Zillow announced a $25 million second-round investment. By then the company had grown to 118 employees. In December