How to add mods to a Minecraft server (Fabric, Forge, NeoForge)
Add mods to a Minecraft Java server. Run Fabric, Forge, or NeoForge, put mod .jar files for that loader and version in the mods folder, and restart.
TL;DR: Switch the server to a mod loader (Fabric, Forge, or NeoForge).
Upload mod .jar files made for that loader and Minecraft version into the
mods folder, then restart. Each player installs the same loader and the
same mods, except mods that only run on the server.
To add mods to a Minecraft server, the server has to run a mod loader first.
Then you copy each mod's .jar file into the server's mods folder and
restart it. A mod only loads if it was built for that loader and that
Minecraft version.
Before you start
Three things must match, or the server won't start.
- The loader. A Fabric mod runs on Fabric and a Forge mod runs on Forge, while NeoForge is a separate loader with its own mods. Check the mod's page on Modrinth or CurseForge for the loaders it supports.
- The Minecraft version. Fabric's mod install guide says a mod should work on the version you play. A mod for one release may not load on the next.
- The dependencies. Many mods need a library mod too. Fabric's
download page says most mods also need
Fabric API in the
modsfolder.
Make a backup first. Paper servers run plugins, not mods. If you want plugins, see the software section of How to set up a Minecraft server.
Add mods on a berrybyte server
Switch the server to a mod loader
In the dashboard, open Settings → Software & updates. Under Server software, pick Fabric, Forge, or NeoForge.
Choose what happens to your world
Under World files, the default is Start fresh, which deletes your current files unless you tick Save my current world first. To keep your world, pick Keep my files instead. Choose the Minecraft release under Software version, then press Switch to and the loader's name.
Upload your mods
Back on Software & updates, the Mods list shows every mod in
the mods folder. Press Upload and choose your .jar files. You can
also press Open folder to use Files, or connect with SFTP.
Restart and watch Console
Uploaded mods load the next time the server starts. Restart it and keep
Console open. When startup ends with a Done line, join with one
player and test a mod before you invite the group.
The Mods list has a switch for each mod, so you can turn a mod off
without deleting it. The trash button deletes the file from mods.
If a mod shows Client-side only, only players need it, so turn it off
there.
Add mods on a server you run yourself
The steps depend on the loader, but the idea is the same each time.
- Install the loader's server files.
- Fabric: pick your versions on Fabric's server page, download the server launcher, and run it with the command the page shows.
- NeoForge: NeoForge's
server guide says to
run
java -jar neoforge-<version>-installer.jar --installServer, then start the server withrun.baton Windows or./run.shon Linux and Mac. - Forge: download the Installer for your Minecraft version from Forge's files page and run it.
- Start the server once. It stops and asks you to accept the EULA. Change
eula=falsetoeula=trueineula.txt. - Start it again. Once it has started, a
modsfolder appears, as NeoForge's guide notes. - Stop the server and copy your mod
.jarfiles intomods. - Start it and read the log for errors.
Which mods go on the server?
Some mods run only on the player's PC, some only on the server, and many on both. Modrinth lists this on each mod page under Supported environments.
| Mod type | Server | Player's PC | Example |
|---|---|---|---|
| Adds blocks, items, mobs, or worlds | Yes | Yes | Most content mods |
| Client-side only | No | Yes | Sodium, a client optimization mod |
| Server-side only | Yes | No | Many admin and performance mods |
A client-side mod in the server's mods folder can stop the server from
starting. Players who join need every mod marked for both sides, at the same
versions as the server.
Can you use Forge mods on Fabric?
No, not by dropping them in. Each loader has its own mods, and Fabric's guide says to use mods made for Fabric. Pick one loader for the server, then choose mods that support it or look for a port on Modrinth or CurseForge.
Fix a server that won't start after adding mods
The error usually names the mod that caused it. Read Console, or open
logs/latest.log in Files. A full crash also writes a file in
crash-reports.
- Missing dependency: the log names a mod that's needed. Add it, for example Fabric API on Fabric.
- Wrong version or loader: the log says a mod needs a different Minecraft version or loader. Replace it with the right build, or see How to update a Minecraft server.
- Client-side mod on the server: turn it off in the Mods list, or remove it.
- Still stuck: turn half the mods off and restart. Keep halving until you find the one that breaks the start.
If the server starts but players can't join, their mods or versions don't match. Work through Can't connect to a Minecraft server and Connection timed out.
How much RAM do mods need?
More mods and more players need more memory. On berrybyte, 8 GB suits light modding and 12 GB suits a busier modded world. The RAM calculator and How much RAM for a Minecraft server help you size it.
Rather run a whole modpack?
A modpack is a ready set of mods with the loader and version picked for you. That's easier than adding mods one by one. See Install a Minecraft modpack, or browse packs you can install in one click.
Mods on berrybyte
Every berrybyte Minecraft plan can run Fabric, Forge, or NeoForge, with automatic backups and manual snapshots. You can upload, turn off, and remove mods from the dashboard. Plans start at $9.95 a month on the Minecraft hosting page.
Frequently asked questions
Where is the mods folder on a Minecraft server?
It sits in the server's main folder, next to server.properties, and it's named mods. The folder appears once the server has started on a loader. On berrybyte, open Files in the dashboard and click mods, or press Open folder in the Mods list under Settings → Software & updates.
Can you use Forge mods on a Fabric server?
No, not on their own, because Fabric's docs say mods must be built for Fabric. Pick the loader most of your mods use. If a mod you need only exists for the other loader, look for a port of it on Modrinth or CurseForge.
Can I join a modded server with a normal Minecraft client?
Usually not. If the server runs mods that add blocks, items, or mobs, each player needs the same loader and those same mods installed. Server-only mods, like many performance or admin mods, don't need a copy on the player's PC.
How much RAM does a modded Minecraft server need?
It depends on the number of mods and players. On a berrybyte server, 8 GB suits plugins or light modding, and 12 GB suits a busier modded world. The RAM calculator gives a starting point for your setup.
Is 200 mods too much for a Minecraft server?
Not by itself, because what the mods do matters more than how many there are. Big mods that add worlds and machines need more RAM than small tweaks. Test a big list on a backup first, and use the RAM calculator to size the server.
Is Forge or Fabric better for a server?
Neither is better for every server. Pick the loader your mods are made for, because that decides what you can run. Check each mod's page on Modrinth or CurseForge, which lists the loaders it supports.