Google Search can predict what you are going to type, while you are typing it. Autocomplete has been a big part of Google's search engine for many years, and for much of that time other Web developers have used the technology in their own sites. Google has decided to put an end to that use.
According to Google, the autocomplete API was never intended to be used outside of its search engine. The API was never made public, though it was never restricted either. Some clever software engineers figured out how to reverse engineer the API and integrate the technology into their own websites.
The company said this isn't the first time an unpublished API that Google created has been reverse engineered. In fact, the company said that the Google Maps API was first used in this way, and months later Google decided to make it a supported API to let engineers use it in clever ways. Google actually supports over 80 different APIs, but autocomplete is not one of them.
Google said it had always intended for autocomplete to complement search. The company evaluated the uses and realized that while other use cases are conceivable, autocomplete is optimized specifically for search functions, and the decision has been made to restrict it to that function alone. Google feels that outside of search, autocomplete -- the way it has been created -- doesn't add meaningful user benefit.
Google has opted to discontinue access to the unpublished, unofficial autocomplete API on August 10. All is not lost for publishers and developers who still want to use autocomplete, though; Google Custom Search Engine will still offer autocomplete in conjunction with the search functionality. Google CSE partners will not be affected by the change. Those who aren't partners can sign up here.