How to Make a Cobblemon Server

The short version

1. Use Minecraft 1.21.1 and Java 21. That is the version the current Cobblemon release (1.8.1, September 2026) is built for.
2. Pick Fabric or NeoForge. Both are supported. On Fabric, Cobblemon needs Fabric API next to it; on NeoForge, it needs Kotlin for Forge. Nothing else is required.
3. Or skip the choice with the official modpack. The Cobblemon team publishes the Cobblemon Official Modpack for Fabric on Modrinth — the easiest starting point.
4. Everyone joins with the same pack. Cobblemon runs on the server and on every player's game, at the same version. A mismatch is the number one reason players get kicked on join.

A small group of friends is comfortable on 5 GB of RAM; bigger groups and bigger packs want 9 GB or more. The details, and which plan fits which setup, are further down.

What Cobblemon needs, checked against its release data

Most "Cobblemon server" tutorials were written for an older version and quietly go stale. These are the current requirements, taken from the mod's own listing on Modrinth:

Two practical consequences. First, the loader decides which other mods you can add: a Fabric mod does not load on NeoForge and vice versa, so if you already have favourite mods, pick the loader they are built for. Second, do not mix versions. Cobblemon updates regularly, and a server on one release with players on another is the classic "why can nobody join" evening.

Official modpack, bare Cobblemon, or a bigger pack

There are three sensible ways to build a Cobblemon server, and the choice mostly comes down to how much you want beyond Cobblemon itself.

• The official modpack. The Cobblemon Official Modpack [Fabric] comes from the same team as the mod. It bundles Cobblemon with a curated set of companion mods, stays in step with Cobblemon releases, and gives every player one thing to install. For most groups this is the right answer.
• Bare Cobblemon. Just Cobblemon and its one required dependency. It is the lightest possible server and ideal if you want to hand-pick everything else — at the cost of doing that picking yourself.
• A bigger community pack. Packs such as COBBLEVERSE build a whole adventure around Cobblemon with many more mods, structures and quests. More to do, and noticeably more RAM and a longer start-up.

Whichever you choose, the rule from the previous section applies: players install exactly the same thing, at the same version, through a launcher that supports Modrinth packs.

Path A: host it yourself

Running a Cobblemon server on your own PC is free and a good way to try it. This is the bare-Cobblemon route on Fabric; NeoForge works the same way with its own installer and Kotlin for Forge in place of Fabric API.

1. Install Java 21. Check with java -version — it must report 21. Older Java refuses to start a 1.21.1 server.
2. Get the Fabric server launcher for Minecraft 1.21.1 from fabricmc.net. It is a single .jar; put it in an empty folder and rename it fabric-server-launcher.jar.
3. Add the mods. Create a mods folder next to it and put the Cobblemon and Fabric API jars for 1.21.1 inside, both downloaded from Modrinth.
4. Start it once, accept the EULA, start it again:

   java -Xms2G -Xmx4G -jar fabric-server-launcher.jar nogui
   # edit eula.txt: eula=true, then run the same command again

   The first start downloads the game files and generates the world; wait for the Done line in the console.
5. Let friends in. On your own network they join with your local IP. From outside, TCP port 25565 has to be forwarded on your router — the port forwarding guide covers that, including the connections where it cannot work.

The catch is the usual one for self-hosting: the server is online only while your PC is, and a creature-collecting world is exactly the kind people want to log into at odd hours. For the wider picture of running any modded server yourself, see how to make a modded Minecraft server.

Path B: one-click on a hosted server

On a HytHost modded Minecraft server the whole setup above is a search box.

1. Pick a plan. 5 GB is enough for the official pack with a small group; the RAM section below matches plans to setups.
2. Open the Modpacks tab in the panel and search for Cobblemon. The installer searches Modrinth and CurseForge, so the official modpack and the big community packs such as COBBLEVERSE are all there.
3. Install and start. The installer lays down the loader, the mods and the configs for the version you picked, and the server runs on the Java that version needs — no Java to install, no launcher to rename.
4. Share the address. Players add it in Minecraft once they have the same pack installed.

Prefer bare Cobblemon? Choose Fabric or NeoForge for 1.21.1 in the panel's version changer and upload the two jars into mods through the file manager.

The server stays online whether your PC is on or not, with NVMe storage, Voxility DDoS filtering and a 99.9% Uptime SLA. If something does not start, live chat support is there from 8 AM to 11 PM (Chișinău time).

How much RAM a Cobblemon server needs

Cobblemon on its own is one of the lighter mods of its size; what drives RAM is the pack around it and how many players are spreading out across the world, because every player loads their own area — and its wild Pokémon — into memory.

These are starting points, not ceilings. Two things help more than adding memory: pre-generate the world with a mod such as Chunky before opening the server, so exploring players do not force terrain to be generated live, and keep the view distance moderate in server.properties. If the server is still short, upgrading the plan in the panel keeps the world. For the general sizing logic, see how much RAM a Minecraft server needs.

Common Cobblemon server problems

Players are kicked on join

Messages about a mismatched mod channel list, or an internal exception right after connecting, almost always mean the player's mods do not match the server's — a different Cobblemon version, a missing companion mod, or a different pack version. It is not RAM and not the network. Have them install exactly the server's pack version.

The server stops at start-up naming a missing mod

Cobblemon's required dependency is not in mods: Fabric API on Fabric, Kotlin for Forge on NeoForge. The console names it; add it and restart.

The server will not start at all and mentions a class version

An UnsupportedClassVersionError means the server was started on an older Java. Minecraft 1.21.1 needs Java 21.

Lag when players explore

Almost always terrain being generated on the fly while several players head in different directions. Pre-generate the world and lower the view distance before reaching for more RAM.

New Cobblemon blocks do not appear in an old world

Pokémon spawn across the whole world, but anything created with the terrain — Apricorn trees and the ores Cobblemon adds — only appears in chunks generated after the mod was installed. Explore new areas, or start a fresh world.