How to Install a Fabric Mod

Installing a Fabric mod follows a simple three-step process: ensure the Fabric loader is installed for your Minecraft version, add the Fabric API to your mods folder, then drop the mod JAR beside it. Most install problems come from version mismatches, so verify every piece targets the same Minecraft version.

Prerequisites

Before you install a mod:

• Fabric loader installed for your Minecraft version (see How to install Fabric loader)
• You've launched the Fabric profile at least once so the mods folder exists
• The mod JAR downloaded

The three-step process

1. Have Fabric loader installed

   Make sure you've installed and launched the Fabric loader for your Minecraft version. If you haven't, follow the Fabric loader installation guide first.

2. Download and add Fabric API

   Download the Fabric API JAR that matches your Minecraft version. Place it in your mods folder. Most mods depend on this.

3. Add the mod JAR

   Download the mod's JAR file and place it in the same mods folder, next to the Fabric API. Don't unzip it—it stays as a JAR.

Launch Minecraft using the Fabric profile and the mod loads automatically on startup.

The mods folder

Your mods folder is located at:

If the folder doesn't exist, run the Fabric profile once and it's created for you.

Fabric API: why you need it

Most Fabric mods depend on the Fabric API, a shared library that provides common utilities for modders. Installing it first prevents crashes from missing libraries. Even if a specific mod claims it doesn't need the API, adding it doesn't hurt and avoids surprises.

What to do when a mod doesn't load

• ✓Mod doesn't appear in the mod list: the JAR is in the wrong folder, or you launched vanilla instead of Fabric. Confirm the path and the profile.
• ✓Crash with "missing class" error: the Fabric API is missing or the wrong version. Download the correct API version for your Minecraft release.
• ✓Version mismatch error in logs: the loader, API, or mod target different Minecraft versions. All three must match exactly (e.g., 1.21, not 1.21.1 if the mod targets 1.21).
• ✓Mod loads but crashes when used: the mod may conflict with another mod or a setting. Try launching with just that one mod to isolate the problem.

Version matching

This is the biggest gotcha. Every piece must target the same version:

Minecraft version: 1.21
Fabric loader version: 1.21 ✓
Fabric API version: 1.21 ✓
Mod version: 1.21 ✓
All match → no crash

If your Minecraft is 1.21 but a mod targets 1.20.1, it won't load. Check the mod's download page for the exact version it supports.

Running multiple mods

Once you have one mod working, adding more is simple:

1. Download each mod JAR
2. Drop them all in the mods folder
3. Launch Fabric
4. All mods load together (assuming no conflicts)

A few mods conflict with each other. If crashes happen after adding a new mod, disable it to confirm that's the cause, then check if the mod author documents the conflict.

FAQ