Short version: a Cobblemon server runs Minecraft 1.21.1 on Fabric or NeoForge with Java 21. Put the Cobblemon jar and its one required dependency in the mods folder, give the server 8GB of RAM for up to 10 players, pregenerate the area around spawn, and leave config/cobblemon/main.json on its defaults until you have a reason to change something. The steps below work on your own machine or on any host that gives you file access. If you would rather not run it yourself, our Cobblemon server hosting plans install Cobblemon modpacks from the panel.
Checked on 30 September 2026 against the Cobblemon listing on Modrinth, the Cobblemon source code and the official Cobblemon wiki. The current release is Cobblemon 1.8.1 (12 September 2026), a patch for 1.8.0 "Make Your Move" (6 September 2026). Both are for Minecraft 1.21.1 on Fabric and NeoForge. See our Cobblemon 1.8 server update guide for what changed.
What you need
Cobblemon is an open-source mod (MPL 2.0) that adds Pokémon to Minecraft, with battles on the Pokémon Showdown engine. The Modrinth listing counts over 800 Pokémon. For a server on the current release you need:
| Item | Cobblemon 1.8.1 |
|---|---|
| Minecraft | Java Edition 1.21.1 |
| Loader | Fabric or NeoForge. The server and every player use the same one |
| Required mod on Fabric | Fabric API |
| Required mod on NeoForge | Kotlin for Forge |
| Java | 21 |
| RAM | 8GB for up to 10 players (table further down) |
The two dependencies are what Modrinth lists as required for 1.8.1. Check the list again when you update, because a new release can add one.
Step 1: Pick Fabric or NeoForge
Cobblemon 1.8.1 came out for both loaders on the same day, so the choice comes from the rest of your mod list. If your group plays a Cobblemon modpack, the pack decides for you. If you build your own mod list, pick the loader that the other mods you want are published for.
For a plain server, install the loader's server for Minecraft 1.21.1: the Fabric server launcher from fabricmc.net, or the NeoForge installer from neoforged.net run in server mode. On a hosted panel you pick the loader and version in the panel instead.
Step 2: Add Cobblemon and its dependency
Download the Cobblemon file for your loader from Modrinth or CurseForge, plus Fabric API (Fabric) or Kotlin for Forge (NeoForge), and put both in the mods folder. Cobblemon is needed on the server and on every client.
Step 3: First start and the EULA
Start the server once. It stops straight away and asks you to accept the Minecraft EULA: set eula=true in eula.txt and start it again. On that second start Cobblemon writes its settings to config/cobblemon/main.json. Since 1.7.0 you can reload that file with /cobblemonconfig reload, although some settings still need a restart.
Step 4: How much RAM a Cobblemon server needs
Every wild Pokémon is an entity with its own AI, and more players means more loaded chunks with Pokémon in them. That is where the memory goes.
| Players | RAM | Space-Node plan, Standard, per month |
|---|---|---|
| Up to 10 | 8GB | MC Diamond, EUR 7.20 |
| 10 to 25, or fewer players with sidemods like Mega Showdown and Cobblemon Additions | 12GB | MC Special 1, EUR 10.80 |
| 25 or more, public server | 16GB | MC Special 3, EUR 14.40 |
These are the sizes we use on our Cobblemon product page. The prices are the Standard prices in the Netherlands, Germany, Poland, Canada, Singapore, India and Australia; the USA adds EUR 0.10 per GB. If you set the Java heap yourself, keep it 1 to 2GB below the server's total memory so Java has room for itself.
Step 5: Pregenerate before players explore
Chunk generation is the heaviest job a Minecraft server does, and riding Pokémon makes players cover ground faster than on foot. Pregenerate a sensible area around spawn with Chunky, which has Fabric and NeoForge builds for 1.21.1. On NeoForge you can also use the built-in /neoforge generate command.
Install Cobblemon before you pregenerate. Cobblemon's structures and Apricorn trees only appear in chunks generated while the mod is installed, so chunks you generate first stay without them.
Step 6: The main.json settings that affect performance
The defaults are fine for most groups. If a profiler shows Cobblemon spawning taking a large share of each tick, these are the settings to look at. The names are the 1.8.1 ones; older configs used worldSliceDiameter and similar names, which 1.8.1 still reads.
| Setting | Default | What it does |
|---|---|---|
pokemonPerChunk | 1.0 | How many Pokémon a chunk may hold when spawning. Lower means fewer entities |
ticksBetweenSpawnAttempts | 20 | Ticks between spawn attempts. Higher means fewer attempts |
maximumSpawningZoneDistanceFromPlayer | 64 | Furthest distance from a player, in blocks, that Pokémon spawn |
spawningZoneDiameter | 8 | Size of the zones spawning picks from. The wiki notes larger values spawn more reliably at a performance cost |
maxNearbyBlocksHorizontalRange | 4 | How far spawn conditions look for nearby blocks. The wiki says lowering it can slightly help performance |
pastureMaxPerChunk | 4 | How many pastured Pokémon can be out in one chunk |
savePokemonToWorld | true | Whether wild Pokémon are saved with the chunk so they are still there after a reload |
Change one value at a time. Measure before and after with spark, for example /spark profiler start --timeout 300, and read which part of the tick got cheaper. Our guide to MSPT and server lag explains the numbers.
Common problems
Players get kicked while joining. The Cobblemon version, the loader or the modpack version on their side does not match the server. Give players the exact version number.
No Pokémon spawn. Check that enableSpawning is true. By default Pokémon spawn between 16 and 64 blocks from a player, so standing in a small enclosed base can look like nothing spawns. Datapacks and sidemods can also change the spawn pools.
Battles feel slow or desync. That is usually the server tick falling behind, not the battle system. Check MSPT, cut entity counts and pregenerate.
Where to host your Cobblemon server
A Cobblemon world works best when it is online whenever one of your players wants to join, not only when someone's own PC is on. Our Cobblemon server hosting page is where to host it. Choose the plan from the table above. For a modpack, the Modrinth and CurseForge modpack installer in the panel sets up the pack and its loader. For a plain Cobblemon server, pick Fabric or NeoForge for 1.21.1 and upload the Cobblemon jar and its dependency to the mods folder.
On the Standard tier these plans run on AMD Ryzen 9 3900X-class CPUs with DDR4 memory in the Netherlands, Germany, Poland, Canada and India. In the Netherlands, Germany, Poland and Canada you can switch to Premium, a Ryzen 9 9950X with DDR5, for the fastest single-thread performance on a busy Cobblemon world. The USA (California and Virginia) has one hardware option with no tier to pick, the Ryzen 9 7950X3D with DDR5, and Singapore and Australia also have a single option, the Ryzen 9 5950X. NVMe storage and DDoS protection are included on every plan. You pick the region in the plan selector before checkout, and the selector shows the price for that region. There are nine to choose from: Netherlands, Germany, Poland, Canada, USA California, USA Virginia, Singapore, India and Australia.