Browser games are electronic games that are played online via the Internet. They are distinct from normal video and computer games in that they do not require any client side software to be installed. There are games that rely solely on client-side technologies such as a web browser and a common plugin such as Java or Flash, whereas other also employ server-side scripting. The latter case are typically (massive) multiplayer games, whereas the client-side games are typically single-player games. A game played in a browser is often called a browser-based game.

Because browser games can be played from any computer connected to the Internet, it has become a severe source of loss of productivity. Although serious studies are lacking about this problem, the phenomenon is increasing and gaming websites with explicit names such as timetrasher.com or boredatwork.com have then appeared.