Proximity voice chat
Voice fades with distance. Choose always on, push to talk, or always off in Voice Chat settings.
Co-op play
Subnautica 2 Multiplayer: 4-Player Online Co-op
Bring up to three friends into one online world, or keep playing solo. Use Friend Codes to add your group, convert an existing solo save if needed, and share a Save Code when someone else needs to host. Buddy System adds proximity voice chat, revives and trading; the October 6 Hotfix 2 improves voice detection and fixes additional Tadpole and player-state issues.
Start here. Up to 4 players online: one host and up to three guests. In the main menu, open Play with Friends to exchange Friend Codes. Keep every player on the same build and branch. Solo saves can convert to multiplayer; local split-screen is unavailable.
Reviewed .
🧑 Solo play
👥 4-player online co-op
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Cross-platform multiplayer
What Buddy System changes in a co-op session
Revive before reprint
A teammate can pick up a downed player, preserving equipment and restoring a small amount of oxygen.
Direct item trading
Interact with a teammate to exchange inventory items without turning the seafloor into a drop pile.
Emotes and Tracking Tags
Use five radial-menu emotes, and place Tracking Tags in carryables for short-range recovery beacons.
Hotfix 1 fixed push-to-talk input and Tadpole passenger oxygen. Hotfix 2, released October 6, follows up with consistent local and remote voice activity detection, a fix for a host appearing dead after your character dies, and Tadpole docking and boundary-recovery fixes. See the EA 1.2 feature summary for the original Buddy System additions.
Player cap: how many people can play together?
4 players is the hard cap. Subnautica 2 is built around a host plus three guests.
The cap applies the same way no matter which mix of platforms your group is on. Steam-only, Xbox-only, or a mixed Steam + Xbox + Game Pass group all share the same 4-player ceiling. There is no server-side workaround in the launch build.
If you have a fifth person, the practical pattern is rotation: hold a "bench" player who swaps in for someone who has to drop, rather than running two parallel sessions on the same save.
How to add friends: Friend Code and Generate Code
Use the in-game friend system for your crossplay group. Unknown Worlds documents the following main-menu flow in its co-op support guide.
- Open Main Menu → Play with Friends.
- If you have your friend’s code, choose Friend Code and enter it to add them.
- To give your own code to a friend, choose Generate Code, copy it and send it to them.
- Start the game in Multiplayer mode and invite the friends you added. Use the save conversion below if the world began as a solo game.
A Friend Code adds another player. A Save Code copies a saved world through Import Save File. Keep the two actions separate when arranging a session.
Convert a solo save to multiplayer without starting over
You can bring friends into an existing single-player world. Open Main Menu → Play Single Player → select your save → Convert to Multiplayer, then host that world.
To switch back, open Main Menu → Host Multiplayer → select your save → Convert to Single Player. Keep a backup of an important world before changing how your group uses it.
Conversion changes the play mode of the selected save. Check cloud saves and Save Codes if you also need to move the world to another player or platform.
Continue when the original host is unavailable
Share the saved world before the next session so another group member can host it. Unknown Worlds supports Save Code sharing across platforms.
- The current host saves the session, opens the multiplayer save list from the main menu and selects the group’s world.
- Choose Save to Cloud and send the generated Save Code to the next host.
- The next host chooses Import Save File in the main menu and enters that code.
- Confirm the imported world has the expected progress, then host it and invite the group. Agree that this is the copy everyone will continue.
This transfers a saved copy. Later progress is not automatically merged with the old host’s copy, so share the latest save again when handing the world back. It also does not establish that an interrupted live session will migrate hosts automatically.
How the networking actually works
A few practical implications worth knowing before a co-op session so you do not blame your router for things it cannot control.
- Matchmaking runs on Epic Online Services (EOS). EOS handles the invite code lookup and the cross-platform plumbing. You do not need an Epic Games Store account on Steam or Xbox; EOS works in the background regardless of where you bought the game.
- Gameplay is peer-to-peer. One player hosts the session, the others connect directly to that host. The host\'s connection quality is the floor for everyone in the group, so if you have the fastest line and the most stable router, you should host.
- Check the platform connection test after versions and invites. If the builds match and Friend Codes work but joining still fails, use the platform’s network troubleshooter and record the error. A connection failure alone does not identify a router setting as the cause.
- Version mismatches block joining. Both players must be on the exact same game version. After a patch, the player who has not updated yet cannot join, even with a valid invite code.
- Hotfix rollout can temporarily split crossplay. Buddy System Hotfix 2 may reach platforms or regions at different times. If one player updates first, a mixed group can see different-version errors until their builds match.
- Hotfix 3 fixed one rejoin-state bug. The official patch fixes clients reverting to a previous position when rejoining multiplayer. If a rejoin problem remains, record host/client role, save state, vehicle state, and exact location change before assuming it is the same symptom.
Platform-specific requirements
Xbox Series X|S
Check that your account has access to the game and a subscription that includes paid console online multiplayer. The purchase entitlement and online multiplayer benefit are separate checks; see the Game Pass guide for the available routes.
Steam, Epic, PC Game Pass
No additional subscription required. The base purchase or active Game Pass on PC includes online co-op.
Friend Pass and Family Sharing
Subnautica 2 does not advertise a Friend Pass. If you are planning a two-player or four-player session, assume each active player needs their own valid access: a purchase on Steam or Epic, Xbox ownership, or an active Game Pass entitlement.
Steam lists Family Sharing support, which helps a household access the game from a shared library. That is different from a free co-op pass. For simultaneous online co-op, the clean setup is one active entitlement per player.
Check the split-screen and couch co-op answer →Recommended co-op flow
Agree on the next objective, shared supplies and a return point before each group dive.
- Pick one player to own base layout and storage. Someone always ends up doing it anyway.
- Keep one explorer near the edge of known areas, not alone in deep zones.
- Use a shared material target before every dive so nobody comes back empty-handed.
- Bring backup power and emergency supplies before pushing into new biomes.
Shared dives
Move through base exits with a clear return plan.
Scout role
One player scans and marks the next safe path.
Multiplayer FAQ
How many people can play Subnautica 2 together?
Subnautica 2 supports up to 4 players in one online co-op session: one host and up to three guests. There is no official 5-player, 6-player, or larger server mode in the Early Access build.
Does Subnautica 2 have crossplay?
Yes. The Steam page lists cross-platform multiplayer, and public launch guides describe cross-play between PC storefronts and Xbox. Use the in-game invite or friend-code flow rather than relying only on platform-native invites.
Does Subnautica 2 have Friend Pass?
No official Friend Pass has been announced for Subnautica 2. Plan for each active co-op player to have their own purchase, Game Pass access, or other valid platform entitlement.
Does Steam Family Sharing let two people play Subnautica 2 co-op together?
Steam lists Family Sharing support, but shared-library access is not the same as a Friend Pass. If two people want to play together at the same time, each player should have their own active access to the game.
Can Steam, Epic, Xbox, and Game Pass players join the same world?
Yes, cross-platform multiplayer is part of the public store listing. Everyone should install available updates, confirm the same branch and build, and use Play with Friends to exchange Friend Codes. Buddy System Hotfix 2 was released October 6; rollout timing can briefly block mixed-platform groups until their builds match.
What does Buddy System Hotfix 2 fix for co-op?
The October 6 patch fixes voice activity detection for local and remote players and a state where the multiplayer host could appear dead after your own character died. It also fixes Tadpole docking and boundary recovery, with an Xbox audio memory-leak fix.
Can I turn my single-player save into a co-op world?
Yes. Open Play Single Player in the main menu, select your save, then choose Convert to Multiplayer. To return to solo, open Host Multiplayer, select the save, then choose Convert to Single Player. You can use an existing world instead of starting over.
Can another friend host our existing world?
Share a saved copy with Save to Cloud from the save list. Your friend uses Import Save File and the generated Save Code, then hosts the imported multiplayer world. Agree which copy the group will continue and transfer the newest save again after a later handoff. This is a saved-world transfer; it does not promise uninterrupted host migration during a live session.
Did Hotfix 3 fix multiplayer rejoin position bugs?
Yes for the specific official symptom: Hotfix 3 fixes clients, meaning non-host players, reverting to their previous position when rejoining a multiplayer session. Nearby desync, save-load, vehicle, or base-state symptoms still need separate repro notes before they can be treated as the same fixed issue.
Did Buddy System Hotfix 1 fix co-op voice and Tadpole problems?
It fixes the Proximity Chat push-to-talk input path and several Tadpole and Haul edge cases, including attached-player oxygen and inventory-sharing states. Update every player and compare the branch and build before treating a remaining symptom as a new desync.
Does Subnautica 2 have proximity voice chat?
Yes. Early Access 1.2 "Buddy System" added proximity voice chat. Teammates become harder to hear as distance increases, and Voice Chat can be set to always on, push to talk, or always off.
Can you revive and trade with other players?
Yes. Buddy System lets teammates revive a downed player before reprinting and directly exchange inventory items. A revived player keeps their equipment and returns with a small amount of oxygen; the downed player can still choose to reprint immediately.
Is Subnautica 2 multiplayer required?
No. Solo play is fully supported. Co-op is optional, so you can play alone or bring up to three friends online.
Does Subnautica 2 have split-screen multiplayer?
No. Subnautica 2 has online co-op, not split-screen, couch co-op, or two players on one PC or Xbox. See the split-screen page for the platform-by-platform answer.
Related guides
Next stops if you're planning a co-op session.
Official support: Friend Codes, convert to multiplayer, convert to single player, and share a save across platforms.