Dead or Alive Online was a free-to-play fighting game for Windows, and a part of the Dead or Alive series. It was the first Dead or Alive game on the PC. Most of the content and gameplay of the game was taken straight from the 2004 title Dead or Alive Ultimate, including the fighting system.
First shown at Tokyo Game Show 2008, Dead or Alive Online was planned for release during the 2008 Beijing Olympics. However, the game never left the open beta stage. The game was in Chinese, but could be accessed internationally.
On January 9, 2010, all Dead or Alive Online servers were closed, rendering the game's multiplayer dead.
Dead or Alive Online was made downloadable for free from the official website, however some extra content, such as additional playable characters and costumes, had to be purchased through microtransactions. Players were required to create a chibi-styled avatar during registration, which represented the player in the community. The player could then enter matches against AI or human players, or take part in quests to unlock items.