Online is a multiplayer game mode in Super Smash Flash 2 that allows players to battle against other players via the Internet. Utilizing the infrastructure of the McLeodGaming Network, it allows players with accounts to do so over a peer-to-peer connection.
Upon logging in, the player enters the Online Lobby, in which they are allowed to create or join a room for other players to play in. Rooms created must contain names of at least four characters, and a password can be added to prevent anonymous players from joining them. Players can also set the latency of input delay of the matches, as well as the maximum amount of players that can join the room. Rooms created can then be joined through a list on the menu, which contains each room's name and creator, as well as the location set in the creator's MGN account settings, how many players can join and have joined the room, the latency setting, and the ping to the server in milliseconds. Rooms are removed from the list when the maximum amount of players has joined, and players can filter the rooms by what rules the creator has set, including the battle type (Stock, Time, or both), whether items are turned on, and whether stage hazards are turned on, as well as whether the creators are friends of the player through MGN. The room list automatically refreshes approximately every 25 seconds, and players can manually refresh the list as well.
Once a room is created, the creator is given the option between the three modes available in Group, renamed as online counterparts: Online Smash, Online Special Smash, and Online Arena. The creator also decides on the rules of each match and, if applicable, the stage played on. The three available modes are all virtually identical to their offline counterparts, except the players must wait for the creator to lock the room before a match begins. While waiting, each player can play separately against a motionless Sandbag on Waiting Room with their selected character.
The creator receives join requests in Online Group, regardless of which menu they are on. Requests can be either accepted or denied, and there is a 20 second timer for requests to be answered to before being denied automatically.
- Prior to its implementation in v0.9b of the demo, online play was one of the most requested features in SSF2. It was first announced at APEX 2014 alongside other player-requested changes in a video.