How to play a Minecraft modpack with friends
To play a modpack together, everyone needs the same mods and one player hosts the world. You don't need a rented modpack server as long as the host plays too.
Install the same modpack on the same version in your launchers. The host adds CraftProxy to the modpack (Fabric), opens a world and types /host. Friends join from the multiplayer menu with their copy of the modpack. They don't need CraftProxy.
Step 1: everyone needs the same modpack
Mods change blocks, items and game rules. That is why every player needs exactly the same mods as the host, otherwise the game refuses the connection or things break. A modpack launcher makes this easy:
- Pick a modpack that runs on Fabric and note the modpack version.
- Everyone installs exactly that version in their launcher.
- If you put together your own mods, the host exports their profile and sends the file to the others. Most launchers can import profiles.
- Start the modpack once and check that it loads to the main menu without errors.
Client-only mods like shaders, minimaps or performance mods can be added by each player, as long as they don't change game content.
Step 2: host the world
The host runs the world for everyone on their PC. For friends outside your network to join, the host puts CraftProxy in the mods folder of their modpack profile. The relay only forwards the connection and doesn't touch world generation or other mods.
How to host with CraftProxy
-
1
Install the mod
Put CraftProxy in your
modsfolder (Fabric). Only you, the host, need it. -
2
Type /host in your world
Open a singleplayer world and type
/hostin chat. CraftProxy opens a tunnel to our relay. -
3
Send the address
Your friends add the address as a server in the multiplayer menu and join.
Your friends only need Minecraft Java Edition on the same version as you, plus the same mods if you play a modpack.
Playing together often? If your friends install CraftProxy too, add each other in the Social menu (key I). You see who is online, chat with them and invite them with one click instead of sending an address every time.
Which Minecraft versions work?
The current version of CraftProxy runs on Minecraft 1.20.1, 1.21, 1.21.1, 1.21.11, 26.1, 26.1.1, 26.1.2, 26.2, 26.3. That includes 1.20.1 and 1.21.1, the versions many popular Fabric modpacks are built on, and every version gets the same features. CraftProxy is a Fabric mod; there is no version for packs on other mod loaders.
What the host PC has to handle
The host's PC runs the world for every player and renders your own game at the same time. With large modpacks that means giving the launcher enough memory and not running too much in the background. When you play far apart, the host PC has to simulate more areas of the world at once.
Good to know: if someone else should host, the host can copy the world folder from saves and pass it on. With the same modpack, the new host opens the world and types /host.
When joining fails
- Error about missing or unknown mods or registry entries: Your mod lists differ. Compare the modpack version or export the host's profile again.
- Disconnected while loading: Often too little memory on the host or the friend. Raise the RAM allocation in the launcher.
- The address doesn't work: The host has to be in the world, and /host has to have shown the address in chat. Check that you sent the address from your current chat.
Questions
Do I need to rent a server for a modpack?
No, as long as the host plays. They host the world on their PC and the others join. You only need a server if the world should stay online without them.
Do my friends need CraftProxy in their modpack?
No. Only the host needs CraftProxy. Friends need the same modpack, but not CraftProxy. For the Social menu with chat and invites, you both need it.
Does CraftProxy work with Forge or NeoForge modpacks?
No. CraftProxy is a Fabric mod and only runs in Fabric modpacks.