How to Install Fabric Mods

What Fabric Is

Fabric is a lightweight mod loader known for fast updates and performance mods. It's popular for mods like Sodium (rendering), Iris (shaders), and Lithium (server optimization). Its mod ecosystem is smaller than the Forge and NeoForge one.

On GameGrid, selecting the Fabric server type installs the Fabric server launcher, which pulls the loader and the Minecraft files itself on first start. You do not download or run a loader installer, and you do not install Java - the platform handles both.

Fabric mods only work on Fabric servers. They won't work on Vanilla, Paper, Forge, or NeoForge. Make sure you selected Fabric as your server type when creating the server.

Where Mods Go

Every Fabric mod is a .jar file, and every one of them goes in the mods/ folder at the root of the server. There is no other location and no per-mod subfolder.

Fabric creates the folder on first start. If it isn't there, you can create it yourself from the Files tab.

Mods that have settings write them to config/ the first time they load. Edit those files from the Files tab with the server stopped; most changes need a restart.

Nothing in mods/ is read while the server is running. Adding or removing a .jar always needs a restart to take effect.

Installing via the Mods Tab

Go to the Mods tab and click "Browse Marketplace." Search for the mod you want. The in-panel marketplace installs Fabric mods from CurseForge. Mods hosted only on other sites like Modrinth or Hangar are not in the marketplace, but you can download them and add them with a manual upload (see below).

The search is scoped to your server's loader, so a Fabric server's results are Fabric builds. This is the safest way to install a mod, because it removes the chance of picking a build for the wrong loader.

Click "Install" to download and place the .jar in the mods/ folder automatically.

The "Installed" tab lists what is on the server and has a "Remove" button for each mod, which deletes its files.

Restart the server for the mod to load.

Installing Manually

1. Stop the server.

2. Download the mod .jar file from Modrinth, CurseForge, or the developer's site. On the download page, filter by "Fabric" and by your exact Minecraft version before downloading.

3. Open the Files tab and navigate to the mods/ folder. Create it if it doesn't exist.

4. Upload the .jar file. You can also upload over FTP if you have a lot of files to move.

5. Restart the server.

Manual uploads are not checked against your loader - the file manager will accept any .jar you give it. This is where wrong-loader mistakes come from, so read the loader label on the download page every time.

Fabric API

Fabric API is required by the large majority of Fabric mods. Install it first - without it, most mods won't load. It's available on Modrinth and CurseForge.

Fabric API is not the same as Fabric Loader. The loader comes with the server; the API is a mod you install separately, into mods/, exactly like any other mod.

It has to match your Minecraft version like any other mod. If you update Minecraft, update Fabric API too.

The symptom of a missing Fabric API is mods that appear to be installed and simply do nothing, or a startup error naming "fabric-api" or "fabric" as a missing dependency.

Why a Forge or NeoForge Mod Will Not Load on Fabric

Fabric, Forge and NeoForge are three separate mod loaders. A mod is compiled against one of them, and it only runs on that one. This is not a version mismatch you can work around - it is a different set of hooks into the game.

Nothing about the file tells you which one it is. Fabric, Forge and NeoForge mods are all .jar files, they all go in a folder called mods/, and the filenames look the same.

A Forge or NeoForge mod dropped into a Fabric server's mods/ folder is either ignored entirely or stops the server from starting. Neither outcome names the real problem clearly, which is why this is the single most common modded-server mistake.

The same is true in reverse: a Fabric mod will not load on Forge or NeoForge.

Fix: check the loader label on the mod's download page and download the Fabric build. If the page has no Fabric build, that mod does not exist for your server - look for an equivalent Fabric mod rather than installing the wrong file.

A mods/ folder copied wholesale from an old server of a different type has the same problem. Do not reuse one across loaders.

Client-Side vs Server-Side Mods

Client-side only: Rendering mods (Sodium, Iris, OptiFine), HUD mods (minimaps), input mods. Do NOT install these on the server - they go on the player's client only.

Server-side only: Performance mods (Lithium), admin tools, anti-cheat. Install these on the server only. Players don't need them.

Both sides required: Mods that add new blocks, items, mobs, or dimensions. All players must install the same mod on their client to join.

If you install a client-side mod on the server, it usually just ignores it. But if a both-sides mod is only on the server, players will get errors when joining.

The Server Won't Start After Adding Mods

This is almost always the mod you added last. Work from that assumption first - it is right most of the time and costs nothing to check.

1. Open the Console tab and read the startup output. Scroll to the first error, not the last line. The first failure is the cause; everything after it is fallout.

2. The error usually names the mod. "Incompatible mod set", "Mod resolution encountered an incompatible mod set", a missing "fabric-api" dependency, or a mixin error with a mod id in it all point at a specific .jar.

3. Stop the server, open the Files tab, and remove the mod you added last from mods/. Start the server again.

4. If it starts, that mod was the problem. Check its page for the right Fabric build, its Minecraft version, and any dependencies it needs.

5. If it still won't start, move every mod out of mods/ - into a new folder like mods-disabled/ so you don't lose them - and start with an empty mods/ folder. A clean start proves the server itself is fine and the fault is in the mods.

6. Add them back a few at a time, restarting between batches, until the failure returns. The last batch you added contains the culprit.

Common causes: a mod built for a different loader, a mod built for a different Minecraft version, a missing Fabric API, a missing library mod the mod depends on, or two mods editing the same part of the game (this shows up as a mixin error).

If the console shows nothing useful, logs/latest.log has the full output and can be downloaded from the Files tab. If you are stuck, open a support ticket and include that log.

Common Issues

Players cannot join: if a mod changes the client as well as the server, every player needs the same mod at the same version. Mismatches show as a connection error or a mod-mismatch screen.