GBA Link Cable

Link Cable lets players connect compatible Game Boy, Game Boy Color, and Game Boy Advance games through Rebit. Use it for games with built-in link features such as trading, battling, or local multiplayer menus.

  • Game Boy Advance rooms support 2, 3, or 4 players.
  • Game Boy / Game Boy Color rooms support 2 players (the classic Game Link Cable had two plugs, and so does ours).

Before You Start

  • Link Cable only appears for Game Boy, Game Boy Color, and Game Boy Advance games.
  • Every player should use a game file they are allowed to use.
  • For best results, every player should start from the same game and ROM revision. Different games that link together also work — for example trading between Pokémon Red and Blue.
  • Game Boy and Game Boy Color games can link with each other, but not with Game Boy Advance games — that matches the real hardware.
  • Save in-game before starting if you want current SRAM progress available in the linked session.
  • Use strong Wi-Fi when possible, and keep every game tab open.
  • Some games may not sync reliably because link behavior varies by game and network conditions.
  • Rollback is a separate beta GBA mode available to every signed-in player on supported browsers. Lockstep remains the default selection.
  • Use Netplay for multiplayer on other consoles.
  • Use Remote Controller if one phone should only act as a controller.
  1. Start a Game Boy, Game Boy Color, or Game Boy Advance game.
  2. Tap the in-game menu button.
  3. Tap Link Cable.
  4. Choose 2P, 3P, or 4P (GBA only — GB and GBC rooms are always 2P).
  5. If the Mode choice appears, keep Lockstep or choose Rollback.
  6. Choose P2P or Edge Link under Transport.
  7. Tap Start Host.
  8. Wait for Rebit to create the room.
  9. Copy the Room Code and send it to the other players.

The host is Player 1. The Link Cable drawer shows the room status, room size, ping, and connected player role.

Lockstep or Rollback?

Lockstep is the existing Link Cable path and remains the safest choice for trading, saving, and games already known to work. It waits for coordinated network ticks, so long-distance play can feel delayed or pause when a player falls behind.

Rollback is a beta mode available for signed-in players with Game Boy Advance games on supported browsers. It applies your local button press immediately while predicting the other players for a short, bounded window. If a late network packet differs from the prediction, Rebit rewinds the complete linked GBA session and quickly replays the corrected frames.

Rollback does not make the internet latency disappear:

  • correct predictions feel immediate, with no configured input-delay frames by default;
  • wrong predictions may show a small visual or audio correction;
  • if a player is missing for longer than the rollback window, everyone pauses safely;
  • a longer disconnect may recover the same seat, or may end the room instead of continuing with invented input.

For Rollback, choose:

  • P2P for nearby players on networks that permit direct WebRTC;
  • Edge Link for long-distance, mobile-data, or 3P/4P rooms when it is available.

Every guest must be signed in and use a supported GBA game/browser. A rollback room cannot be joined through stable Link Cable, and Rebit never silently converts one type into the other. If rollback setup fails, leave it and create a new Lockstep room.

Choose a Connection Mode

The host picks the connection mode when creating the room. Joining players use the host's mode automatically. A room cannot change modes — create a new room to switch.

P2P

P2P connects players directly to each other. It usually has the lowest network delay.

Use P2P when:

  • Players are in the same country or region.
  • You are trading, playing co-op, or doing anything casual.
  • You are not sure which mode to pick. Start here.

Example: you and a friend across town want to trade a Pokémon. Create a room with P2P, send the Room Code, trade, done.

Some networks block direct connections. If the room gets stuck on Connecting, or the other player's game keeps freezing and jumping, switch to Edge Link.

Edge Link (Existing Rooms)

Edge Link routes the room through Rebit's servers around the world. It connects reliably on networks where P2P cannot.

Use Edge Link when:

  • P2P will not connect, or connects but keeps stuttering.
  • A player is on mobile data or a phone hotspot.
  • A player is on strict Wi-Fi, such as a campus, office, or hotel network.

The current room setup no longer offers this older protocol. Rebit can still join existing rooms for compatibility. New rooms use the current Edge Link protocol.

Edge Link lets you pick a server region in Lockstep mode (Auto, Asia-Pacific, Oceania, North America West or East, Europe West or East). Leave it on Auto normally. If the session feels worse than it should, pick the region closest to the middle point between the players.

Edge Link

For Lockstep rooms, Edge Link lets the server pace the whole room so every player feels the same delay. It also stays smooth over long distances and pauses cleanly when a player's connection blips.

Use Edge Link when:

  • The game is competitive and timing matters, such as racing or link battles.
  • The room has 3 or 4 players.
  • Players are on different continents.
  • A long Edge Link session keeps stuttering and you want steadiness over raw speed.

Example: four faraway friends can choose Edge Link so strict NAT or mobile networks do not block the room.

Save export is disabled while a Lockstep Edge Link session is running. Export your save before starting the room if you want a backup.

Which Mode Should I Pick?

Situation Mode
Friends nearby, casual play or trading P2P
Will not connect, mobile data, or strict Wi-Fi Edge Link
Session works but feels rough Edge Link with a manual region
Competitive games, 3P or 4P, or faraway friends Edge Link

Join by Room Code

  1. Start a matching game from your library (same system family as the host's room).
  2. Tap the in-game menu button.
  3. Tap Link Cable.
  4. Type the Room Code from the host.
  5. Tap Join.
  6. Wait while Rebit prepares the linked session.

Joining players are assigned as Player 2, Player 3, or Player 4 depending on the room size and join order. After everyone is connected, use the game's own link cable menu to trade, battle, or start multiplayer.

Join from Discover

  1. Tap Discover in the bottom dock.
  2. Open the active rooms area.
  3. Find a room marked Link Cable.
  4. Tap Join.
  5. Choose a game from your library that matches the room's system family.
  6. Rebit opens the game and joins the Link Cable room.

If you do not have a matching game in your library, upload one first.

Link Cable uses the latest in-game SRAM save for each player. If Rebit cannot find an in-game save, the linked session starts with a blank save.

  1. Open Link Cable while the session is running.
  2. Tap Save.
  3. Wait for Rebit to store the Link Cable in-game save.

This saves the game's battery-backed in-game save, not a regular save state.

In Rollback, Save first pauses every player at the exact same confirmed frame/hash. Rebit exports each player's own in-game SRAM only after that barrier finishes. Wait for the save confirmation before resuming or leaving. Normal save states are unavailable during rollback because loading one player's state would break the whole linked session.

Pause, Resume, or Leave

  • The host can tap Pause or Resume in the Link Cable drawer.
  • In Rollback, pause/resume uses a confirmed group barrier; it can take a moment while all players acknowledge the same frame.
  • Any player can tap Leave to disconnect from the room.
  • Tell the other players before leaving, especially before trading or saving inside the game.
  • In 3P or 4P rooms, ask every player to finish the game's own save routine before anyone leaves.
  • If Link Cable is disabled, confirm the game system is Game Boy, Game Boy Color, or Game Boy Advance.
  • If joining fails, check the Room Code and ask the host to copy it again.
  • A Game Boy or Game Boy Color game cannot join a Game Boy Advance room, and the other way around. Rebit blocks the join with a message when the systems do not match.
  • If the room never leaves Connecting on P2P, recreate it with Edge Link.
  • If an Edge Link session feels laggy, recreate it with a manual region near the players.
  • If Rollback is missing, verify that you are signed in with a GBA game on a supported browser and that the server has at least one rollback transport available. The service may also be temporarily stopped during an incident. Use Lockstep.
  • If Rollback reports that it reached the prediction horizon, keep the page visible and wait briefly for the missing player. Recreate a stable room if it cannot recover.
  • Visible corrections are possible in rollback and do not by themselves mean a desync. A reported confirmed-hash mismatch does: stop before trading or saving and recreate the room.
  • If a room appears in Discover as Link Cable, join it with a GBA game instead of the normal Netplay drawer.
  • If the game behaves differently for each player, restart with the same game and ROM revision on every device.
  • If a 3P or 4P session fails, run a short 2P test first, then add the remaining players after confirming the game can link reliably.
  • If Rebit reports a desync, restart the room before trading or saving.
  • If the mGBA Dual core fails to load, refresh both game tabs and try again.
  • Close unused browser tabs if the linked session feels slow.