Instagram is an American photo and video-sharing social networking service owned by Facebook, Inc. It was created by Kevin Systrom and Mike Krieger, and launched in October 2010 on iOS. A version for Android devices was released in April 2012, followed by a feature-limited website interface in November 2012, a Fire OS app on June 15, 2014 and an app for Windows 10 tablets and computers in October 2016. The app allows users to upload photos and videos, which can be edited with filters and organized with tags and location information.

Instagram was originally distinguished by only allowing content to be framed in a square (1:1) aspect ratio with 640 pixels to match the display width of the iPhone at the time. These restrictions were eased in 2015, with an increase to 1080 pixels. The service also added messaging features, the ability to include multiple images or videos in a single post, as well as "Stories".

After its launch in 2010, Instagram rapidly gained popularity, with one million registered users in two months, 10 million in a year, and 1 billion as of May 2019. In April 2012, Facebook acquired the service for approximately US$1 billion in cash and stock. As of October 2015, over 40 billion photos had been uploaded. Although praised for its influence, Instagram has been the subject of criticism, most notably for policy and interface changes, allegations of censorship, and illegal or improper content uploaded by users.

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