Revisiting Google Suggest, or Autocomplete

With the arrival of Google Instant, we've been receiving some questions around how the autocomplete suggestions are generated, and how this might affect advertisers. Google Instant utilizes the same technology as Google Suggest (now called Autocomplete), so it's worth revisiting this feature to learn more.

Features: Autocomplete (from Google Web Search help centre)

As you type in the search box on Google Web Search, Google's autocomplete algorithm offers searches that might be similar to the one you're typing. Start to type [car ] and you'll be able to pick searches for car tax, car games and car insurance (to name just a few). Type some more and you may even see a link to the page you are looking for.

How autocomplete works

As you type, Google's algorithm predicts and displays search queries based on other users' search activities. These searches are algorithmically determined based on a number of purely objective factors (including popularity of search terms) without human intervention. All of the predicted queries shown have been typed previously by other Google users. The autocomplete dataset is updated frequently to offer fresh and rising search queries. In addition, if you're signed in to your Google Account and have Web History enabled, you may see search queries from relevant searches that you've done in the past.