Google Suggest provides a list of query suggestions when users start typing in the search box, helping to formulate queries and reduce spelling errors. The feature is similar to Google's "did you mean?" feature but works in real time. Google Suggest can provide refinements for partially typed words. For example, by typing in "prog," Google Suggest may provide words like "programming," "programming languages, "progesterone," "progressive." Users then pick a term by scrolling up or down the list.

The company said that Suggest is based on algorithms that use a wide range of information to predict the queries users most likely to want to see.

"Google Suggest uses data about the overall popularity of various searches to help rank the refinements it offers," Google said on its FAQ page. "An example of this type of popularity information can be found in the Google Zeitgeist. Your information is private. Google Suggest does not base its suggestions on your personal searches, although it does use information about the relative popularity of common searches to rank its suggestions. Your Google Suggest searches, like all the information you send to Google, are covered under Google's privacy policy."

Google Suggest has been in the making for four years and will gradually be rolled out this week, the company said. Suggest will be available by default on the search engine homepage. Users can also go back to a regular Google homepage without the Suggest feature.

To use Google Suggest, browsers must be Internet Explorer 6.0 (or newer), Netscape 7.1 (or newer), Mozilla 1.4 (or newer), Firefox 0.8 (or newer), Opera 7.54 (or newer), or Safari 1.2.2 (or newer). Both JavaScript and cookies must also be enabled. Suggest can also be downloaded in the latest version of the Google Toolbar for either Internet Explorer or Firefox.