Google announced that on August 10, 2015, they will be closing down their Autocomplete API.
Google said the unsupported API had no official restrictions and saw the API being used in both ways they found useful and in other ways that were not so useful. That being said, Google said the Autocomplete API doesn’t “provide a meaningful user benefit” other than being paired to Google Web search.
Peter Chiu from Google wrote:
In the interest of maintaining the integrity of autocomplete as part of Search, we will be restricting unauthorized access to the unpublished autocomplete API as of August 10th, 2015. We want to ensure that users experience autocomplete as it was designed to be used — as a service closely tied to Search. We believe this provides the best user experience for both services.
For publishers and developers who still want to use the autocomplete service for their site, we have an alternative. Google Custom Search Engine [CSE] allows sites to maintain autocomplete functionality in connection with Search functionality. Any partner already using Google CSE will be unaffected by this change. For others, if you want autocomplete functionality after August 10th, 2015, please see our CSE sign-up page.
Google also believes that many SEM and keyword tools use this API to generate new keyword ideas. This may affect some of the tools you use.