According to Google, because the unsupported API didn’t have any official restrictions, the API was being used in ways that was both useful and not so useful. Google said that the Autocomplete API isn’t providing any meaningful user benefit, other than the fact it’s paired with 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of maintaining the integrity of autocomplete as part of Search, we will be restricting unauthorized access to the unpublished autocomplete API as of August 10th, 2015.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 [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][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.
Since a number of people, as well as SEM and keyword tools use the Autocomplete API to generate new keyword ideas, this could very well affect some of the tools that we use.
Original Source by Barry Schwartz[/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]