How to Make a Cobblemon Server: Fabric, NeoForge and COBBLEVERSE

To make a Cobblemon server you need Minecraft 1.21.1, a Fabric or NeoForge loader, and two jars: Cobblemon and its one required library. That's the whole server side. The part people get wrong is the client. Players can join from Cobblemon's official modpack or from a big pack like COBBLEVERSE, and those packs change what the server has to run.

This guide starts with that choice, then covers each setup on a GameServerKings server, the settings in Cobblemon's config file, and the questions that come up once friends start joining.

Current versions (September 2026)

Cobblemon 1.8.1 for Minecraft 1.21.1, released 12 September 2026, in a Fabric build and a NeoForge build. Cobblemon is Java Edition only. Its own install guide says it "will not be available to play on Bedrock Edition."

Pick the Server You Are Building

The official modpack is the reason plain Cobblemon is the easy option. Most of its mods are client visuals and menus. Its Modrinth page says it "will allow clients to connect to servers that only run Cobblemon and Fabric API." You don't need to copy the modpack onto the server.

A modpack like COBBLEVERSE is different: it adds structures, datapacks and content mods, and it pins an older Cobblemon. Its players can only join a server running the same pack. That's covered further down.

Plain Cobblemon on Fabric

1. Startup tab: set Framework to FABRIC, Minecraft Version to 1.21.1, and Docker Image to Java 21. Cobblemon's jar declares java 21.

2. Settings → Reinstall. The install script fetches the newest stable Fabric loader (0.19.5 at the time of writing) and puts the server launcher in place as server.jar. Cobblemon needs loader 0.17.2 or newer, so the current loader is fine. The Build Number variable doesn't apply to Fabric. Your world, mods/ and config/ survive a reinstall.

3. Download two jars from Modrinth, both for 1.21.1 and Fabric:

   • Cobblemon: Cobblemon-fabric-1.8.1+1.21.1.jar
   • Fabric API: Cobblemon 1.8.1 requires 0.116.6+1.21.1 or newer (0.116.17 is current)

4. Upload both into mods/. Use SFTP for Cobblemon. The Cobblemon jar is about 137 MB, and most of our nodes cap browser uploads at 100 MB. Connect with any SFTP client on port 2022 (How to upload files via SFTP). Fabric API is small enough for the Files tab.

5. Start the server. You don't need Fabric Language Kotlin as a separate download. The Cobblemon jar bundles it.

Plain Cobblemon on NeoForge

The steps are the same with two changes. Set Framework to NEOFORGE (the script installs the newest non-beta NeoForge for 1.21.1). Then put Cobblemon-neoforge-1.8.1+1.21.1.jar plus Kotlin for Forge, its required dependency on NeoForge, in mods/. Choose this only if you want other NeoForge mods beside Cobblemon, because the Fabric and NeoForge builds can't be mixed. Every player must be on the same loader as the server.

Switching an existing Paper world

New servers start on Paper. If a Paper-created world fails its first modded start with Missing data pack paper, set Extra Flags to --safeMode, start once, stop, and clear the flag. The install log prints the same advice.

Running a COBBLEVERSE Server

COBBLEVERSE is the most-downloaded Cobblemon modpack on Modrinth after the official one. Two facts shape a server for it:

• It pins its own Cobblemon version. COBBLEVERSE 1.7.42 (21 July 2026) ships Cobblemon-fabric-1.7.3+1.21.1.jar, not 1.8.1. Run the pack's jars, not the newest ones.
• Its .mrpack doesn't split client and server mods. All 168 files in 1.7.42 are marked as required on the server. That includes client mods like Sodium and Iris. Both declare "environment": "client" in their fabric.mod.json, and Fabric's spec says a mod is considered for loading only in the environments it lists, so a dedicated server skips them.

The practical route is to build the server folder on your own computer and upload it:

1. Install COBBLEVERSE in the Modrinth App (or Prism) at the version your players will use.
2. From that instance, copy mods/, config/ and datapacks/ into a new folder. COBBLEVERSE's structures and trainers come from datapacks in that datapacks/ folder, loaded by the Global Packs mod, so don't leave it out.
3. Zip the folder, upload it over SFTP, and Unarchive it in the Files tab. It is far over the 100 MB browser limit.
4. Set Framework FABRIC, Minecraft Version 1.21.1, Docker Image Java 21, then reinstall. The pack was built on Fabric loader 0.18.4; the script installs the newest stable one. We haven't booted COBBLEVERSE on that newer loader ourselves, so if the console shows it refusing to start over the loader version, contact support.
5. Start with a fresh world, so the pack's structures generate.

COBBLEVERSE's page asks for 6 GB of RAM or more for multiplayer. Its terms also set rules for servers:

• "You are completely free to host private servers for friends, family, or small private communities."
• On a public server with "a commercial shop (ranks, perks, virtual items, or monetary transactions)", you "MAY NOT use COBBLEVERSE's custom structures, trainers, or datapacks".
• You "MAY NOT name or advertise your server as a "COBBLEVERSE Server"". "COBBLEVERSE Compatible" is allowed.

Tuning Cobblemon: config/cobblemon/main.json

Cobblemon writes its settings to config/cobblemon/main.json on first start. Edit it with the server stopped. The Cobblemon wiki's Config page lists every key. These are the ones server owners change most:

Admin commands such as /spawnpokemon <pokemon> [attributes] (alias /pokespawn) need operator permissions. The wiki notes they "require cheats to be enabled". The op levels are explained in Minecraft Op Permission Levels.

Memory and Performance

For the heap, the only figure Cobblemon's team publishes is for the official modpack on a client: "a minimum of 2.5 GB of memory. Use 3 GB or more for best performance." A server holds every player's loaded area at once, so treat that as the floor for a couple of friends. For COBBLEVERSE, plan on the pack's own 6 GB. Our servers start with -XX:MaxRAMPercentage=95.0, which gives the heap 95% of the plan's RAM, so there is no memory field to set. More on sizing is in Minecraft Server RAM and JVM Flags.

Cobblemon's spawner does its work near players. If the server logs Can't keep up! with several people spread out, lower pokemonPerChunk before anything else, then check Diagnosing Lag.

Common Questions

A friend joins and gets a mod-mismatch or "channel" error. They aren't on the same Cobblemon version or loader as the server, or they're running a pack with content mods the server doesn't have. Match versions exactly. Mismatched mod channel list explains how to read the message.

Can Bedrock players join? No. Cobblemon is Java Edition only.

Can I update Cobblemon mid-world? Back up first (How to create a backup), then swap the jar and restart. Update players at the same time. On a modpack server, wait for the pack to update instead.

Is there an official Cobblemon server I'm competing with? No. The team says "Cobblemon does NOT have an official server." Public servers are listed on cobblemon.com/en/servers.

What else can go wrong? The general modded-server workflow (server packs, updating without losing a world, getting everyone onto the same version) is in How to Make a Modded Minecraft Server. For crashes, Reading Minecraft Server Logs and Crash Reports.

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