IO games, short for "browser-based multiplayer online games," are a popular genre of online games known for their accessibility and simplicity. These games are typically designed to be played directly in a web browser, requiring no downloads or installations. IO games often feature competitive, fast-paced gameplay and a minimalist, easy-to-learn design.

They encompass a wide range of genres, from action-packed battle royales to strategic multiplayer challenges. Players can join lobbies with people from around the world, making IO games a social and competitive experience.