Roblox is an online gaming platform and game creation system developed by Roblox Corporation in 2006 that allows users to write games and play games created by other users. Founded in 2004 by David Baszucki and Erik Cassel and launched in 2006 , the platform hosts multiple types of games created by users and coded using the programming language Lua. For most of its history, Roblox was relatively small, both as a platform and as a company. Roblox began growing rapidly in the second half of the 2010s, and that growth was accelerated by the COVID-19 pandemic.

Roblox is free to play with in-game purchases. Players need Robux, the virtual currency used in Roblox, to purchase items and games. As of August 2020 , Roblox had more than 164 million monthly active users, covering more than half of the children under the age of 16 in the United States. Since its release, Roblox has received generally positive reviews from critics.