To host a modded Minecraft server, you pick one mod loader, install its server files, put the same mods on the server and on every player's game, accept the EULA and open port 25565 if friends join from outside your network. Mods are Java Edition only, so none of this applies to Bedrock. The loader and the Minecraft version have to match on both sides, and that one rule causes most failures.
Choose Fabric or NeoForge for your server
The mods you want decide the loader. A Java mod runs only with the loader its build was made for, installed for the same Minecraft version. Check each mod's loader list before you commit. For example, ServerCore has Fabric builds for 1.17.1 to 26.3 and NeoForge builds for 1.20.2 to 26.3. Its Forge builds are STOPPED at 1.20.4 (last build 2024-11-22 for 1.20.1), so Forge is a poor pick for new worlds if you want that mod. For a wider comparison, read Fabric vs Forge vs NeoForge.
Fabric API is a library mod that requires Fabric Loader, and its jar goes in the `mods` folder like any other mod. It is listed as optional on both sides.
Pick your hosting route, your own PC or a rented host
Hosting at home is free if you own the hardware and gives you full control. The costs are upload limits, power outages, DDoS exposure and a PC that must stay on. A rented host brings stable bandwidth, DDoS protection and backups, in exchange for a monthly fee and a control panel to learn.
Modrinth Hosting (listed as a beta release) runs Vanilla, Fabric, Forge, Quilt and NeoForge. The Small plan is $10 a month billed quarterly for 4 GB RAM, and a customized plan starts at $5 a month. Every server includes SFTP access, a file manager and 15 off-site backups. You can also move a finished local server to any host by zipping the server folder, uploading it over SFTP, then choosing the right Java version and startup file in the panel.
Install the server files and Java
Running your own server needs a Java Runtime on your machine, and you must be able to run Java from the command line. On Windows that can mean editing the PATH environment variable. Java versions matter: modded Minecraft commonly needs Java 17 for 1.18 and newer, while older packs may need Java 8. Check your loader's requirements and see how to update Java if yours is old.
- 1.Create a clean empty folder for the server.
- 2.Get the server files for your loader and Minecraft version. Our guides cover Fabric and Forge and NeoForge on the player side.
- 3.If a Forge-style installer is used, one host walkthrough has you run it with Java, choose Install server and point it at the server folder. Some modpacks ship a ready-to-run script instead, and the pack's README comes first.
- 4.Start the server once so it creates its default folders.
Add mods and match them with the client
Put each mod's .jar file, and every required dependency's .jar, in the server's `mods` folder. Then make the players' side identical. If you add or remove a mod on the server, update every player's profile too, and keep `mods` and `config` in sync after manual changes. A mismatch shows up as a missing-mods error or a mod version mismatch.
Not every mod belongs on both sides. ServerCore is server required and client unsupported. Very Many Players is server required with the client optional, and its creator says it is still in early development, so expect breakage. Read how client-side and server-side mods differ before you copy a whole mods folder across.
A modpack is the shortest route to a matched setup. The Cobblemon Modpack for Fabric covers Minecraft 1.20.1 to 1.21.1, is required on both client and server, and its creators say clients can also join servers running only Cobblemon and Fabric API. Plugins are a different system, covered in installing plugins on Paper or Spigot.
Accept the EULA and start the server
Without `eula=true` in `eula.txt`, the server stops on first launch. Open the file, set `eula=true`, and launch again. Use the included script (`run.bat` on Windows, `./run.sh` on Linux and macOS) if your loader or pack provides one. To run without the graphical interface, start with `nogui`; leave it out if you want the interface.
Do not give Java all your memory. On an 8 GB machine, allocate 4 to 6 GB and leave headroom for the operating system. One host's rough guide is 4 to 6 GB for small packs, 6 to 8 GB for medium and 8 to 12 GB or more for heavy ones. Start view distance modest, around 8 to 10, and raise it only if the server keeps up.
Open the port so friends can join
On a home network, forward port `25565` TCP to the PC running the server, and allow it through the firewall. Players connect with your public address. On a rented host you use the address and port the panel assigns, and nothing needs forwarding. If you reach a friend only on your own network, forwarding is not needed. Control who can join with a whitelist.
Fix common startup and connection problems
- Server stops at first launch with an EULA message. Set `eula=true` in `eula.txt`.
- Java version errors. Install the Java version your loader or pack requires and update the launch command.
- Crash on boot. Read `latest.log` in `/logs/` and any crash report. Usual causes are a corrupt config, a mod missing its dependency or an outdated library.
- Friends cannot connect. Recheck the port forward, the firewall and that everyone runs the same mods. See Can't Connect to Server.
How to set up a self-hosted modded 1.12 server for modpacks
Frequently asked questions
Is the Minecraft server software free?
Yes. The server software for Java Edition is free to download from the Minecraft website. Your costs come from the hardware you run it on or a rented host, and downloading it means agreeing to the Minecraft End User License Agreement.
Can Bedrock players join a modded Java server?
Not through anything in this setup. Mods are Java Edition only and Bedrock cannot load them, and the server software on the Minecraft site is a separate download for each edition. A modded server means Java players with matching mods.
How much RAM does a modded server need?
It depends on the mods. One host suggests 4 to 6 GB for small packs and 8 to 12 GB or more for heavy ones, always leaving room for the operating system. Modrinth Hosting sells 4 GB for 1 to 5 friends with a few light mods.
Do players need the same mods as the server?
Mostly yes. Keep the same modpack version, mods and configs on both sides. Some server-only mods, such as ServerCore, are unsupported on the client, so check each mod's side before copying files to players.
