How to Install NeoForge Mods on a Minecraft Server

To install NeoForge mods on a Minecraft server, run the NeoForge server for your exact Minecraft version (21.1.x builds for 1.21.1, 26.1.2.x for 26.1.2), put each mod's .jar in mods/, and restart. Use mods marked NeoForge for that version: Forge mods only load on the 1.20.1 build. Keep client only mods off the server. Mod settings live in config/, but a copy in world/serverconfig/ overrides it, which is why some edits seem ignored.

What you are working with

NeoForge is the community fork of Forge that most new big mods and modpacks use from Minecraft 1.20.2 on. Since 26.1 its version numbers match Minecraft: in 26.1.2.114, the first three parts are the Minecraft version and the last is the NeoForge build (NeoForged, 26.1 release notes).

Which NeoForge version do I need?

Choose by mods, not by newest. If the mods you want are on 1.21.1, run 1.21.1.

Forge mods vs NeoForge mods

On CurseForge and Modrinth, filter by NeoForge and your Minecraft version. Many mods publish separate Forge and NeoForge files with nearly identical names, so check the loader label on the exact file you download.

Before you start

• Pick the Minecraft version that all your important mods support.
• Back up. Content mods change the world, and removing one later can break chunks or items.
• Separate client mods. Shaders (Iris, Oculus), minimaps, zoom and menu mods go on players' games only.

Step 1: Install the NeoForge server

Self hosting, download the installer for your version from neoforged.net and run:

java -jar neoforge-21.1.253-installer.jar --installServer

It creates libraries/, a run.sh start script and user_jvm_args.txt. Accept eula.txt and start once, so mods/, config/ and the world exist. An existing vanilla world of the same version loads fine.

Step 2: Add the mods

1. Stop the server.
2. Upload every mod jar and every library it depends on (Kotlin for Forge, Architectury, GeckoLib, Curios and so on) into mods/.
3. Start and watch the log. NeoForge lists missing or wrong dependencies by name with the version range it wants.

Step 3: Change mod settings

Start the server once after adding a mod so it writes its config files, then stop it and edit them in config/. Server type configs (often named <mod>-server.toml) are synced to players when they join, so everyone plays by the server's values.

The gotcha: world/serverconfig quietly wins

On old Forge, server configs lived only inside the world, in world/serverconfig/. NeoForge moved them to the shared config/ folder, but kept the world folder as an override: per the NeoForge config docs, a SERVER config can be overridden per world by putting a file in world/serverconfig/.

That causes a classic problem. You upload a world from a modpack, a single player save or an older Forge server, and its serverconfig folder still holds create-server.toml or similar. You change the value in config/, restart, and nothing happens, because the copy in the world folder takes priority.

The fix:

1. Stop the server.
2. Open world/serverconfig/.
3. Either edit the file there, or delete it so config/ applies.
4. Start again.

When a setting will not stick, check both places before anything else.

Common problems

• A mod is ignored or reported as not a valid mod file: it is a Forge or Fabric build, not NeoForge. Get the NeoForge file for your version.
• "Missing or unsupported mandatory dependencies": add the library named in the log, in the version shown.
• Crash with "invalid dist DEDICATED_SERVER": a client only mod is on the server. Remove the jar named in the crash.
• Config edits do nothing: a copy in world/serverconfig/ overrides config/.
• Players kicked with a mod mismatch: their mod versions differ from the server's. Share a modpack so everyone has the same list.
• Java class version error on start: 1.21.1 needs Java 21, 26.x needs Java 25.

NeoForge mods on GamezServers

On a Minecraft server from GamezServers, choose NeoForge in Settings, set the Minecraft version, and press Update game. The newest stable NeoForge build for that version is picked for you. To pin an exact build, fill in Exact NeoForge version with the full number, such as 21.1.253 or 26.1.2.114. NeoForge is installed for you and your world stays. Memory comes from your plan, so user_jvm_args.txt is not used. Upload mods with the file manager or SFTP, and press Backup first. For a full pack, see how to install a Modrinth modpack on a Minecraft server, or compare loaders in Forge mods on a server.

FAQ

Can NeoForge run Forge mods?

Only on Minecraft 1.20.1. From 1.20.2 on, Forge and NeoForge mods are not compatible, so use NeoForge builds.

Which NeoForge version goes with Minecraft 1.21.1?

The 21.1.x builds. The newest in October 2026 is 21.1.253.

Where are NeoForge server configs stored?

In the server's config/ folder, unless a copy in world/serverconfig/ overrides it for that world.

Do players need NeoForge to join a NeoForge server?

Yes, when the server has content mods. They need NeoForge for the same Minecraft version and the same mods.