Flickr (pronounced "flicker") is an image hosting and video hosting website, and web services suite that was created by Ludicorp in 2004 and acquired by Yahoo in 2005. In addition to being a popular website for users to share and embed personal photographs, and effectively an online community, the service is widely used by photo researchers and by bloggers to host images that they embed in blogs and social media.

The Verge reported in March 2013 that Flickr had a total of 87 million registered members and more than 3.5 million new images uploaded daily.In August 2011 the site reported that it was hosting more than 6 billion images and this number continues to grow steadily according to reporting sources.Photos and videos can be accessed from Flickr without the need to register an account but an account must be made in order to upload content onto the website. Registering an account also allows users to create a profile page containing photos and videos that the user has uploaded and also grants the ability to add another Flickr user as a contact. For mobile users, Flickr has official mobile apps for iOS,Android,PlayStation Vita, and Windows Phone operating systems, and an optimised mobile website.