[1] In April 2011, the United States Department of Justice Antitrust Division approved Google's $700 million purchase of ITA Software.

[3] An innovation of Google Flights is that it allows open-ended searches based on criteria other than the destination; for example, a user may search for flights within a range of times and a budget and be offered various destination choices.

[4] Alternatively, a user can select a destination, and Google Flights will calculate every price for each day of the next 12 months, visualized in a graph or table.

This move faced a backlash from environmental activists and the scientific community.

[5] The service was immediately compared to competitors such as Expedia, Orbitz, Kayak.com, and Bing.