How to Install Minecraft Mods (Java Edition)

Mods only work on Java Edition. Bedrock uses add-ons, not mods. This guide covers Fabric, Forge, and NeoForge from a clean install — where the folders are, what to download, and how to diagnose the most common crash on first launch.

Before you touch anything

You need three things in place before you download a single mod.

Minecraft Java Edition installed and launched at least once. The launcher must have created a .minecraft folder on your system.
Java runtime matching the Minecraft version you plan to play. The Minecraft launcher bundles its own Java, but third-party loaders sometimes need a specific version on your PATH.
The exact Minecraft version the mod supports. A mod built for 1.20.1 will not load on 1.20.2. This is the single most common reason a mod "doesn't work."

Quick check: open the Minecraft Launcher, hover over the version you want to mod, and note the exact string — 1.21.4, 1.20.1, etc. You will need this string for every mod you download.

Step 1: Choose a mod loader

Minecraft has three main mod loaders. They are not interchangeable — a Fabric mod will not run on Forge, and a Forge mod will not run on Fabric.

Loader	Best for	Mods available
Fabric	Performance mods (Sodium, Iris, Lithium), light modpacks, fast updates	Hundreds, growing fast
Forge	Large content mods (Create, Mekanism), modpacks, tech mods	Thousands
NeoForge	Modern fork of Forge for 1.20.2+, growing ecosystem	Thousands (inherited)

Pick based on the mod you want, not the other way around. If you want Sodium and Iris, you need Fabric. If you want Create, you need Forge or NeoForge. Check the mod page before you install a loader.

Step 2: Install the loader

Fabric

Go to fabricmc.net/use/installer and download the installer for Windows, macOS, or Linux.
Run the installer. Under the "Minecraft Version" dropdown, select the exact version you plan to mod.
Click Install. The installer adds a profile to the Minecraft Launcher.
Open the Minecraft Launcher. A new profile named fabric-loader-{version} appears in the version dropdown.

Forge

Go to files.minecraftforge.net and select your Minecraft version.
Download the Installer (not the MDK).
Run it. Select Install client.
Open the Minecraft Launcher. A new profile named forge-{version} appears.

NeoForge

Go to neoforged.net and select your Minecraft version.
Download the installer.
Run it. Select Install client.
Open the Minecraft Launcher. A new profile named neoforge-{version} appears.

Watch out: Forge and NeoForge installers sometimes fail silently on systems with non-standard Java installations. If the profile does not appear in the launcher, check the installer log for Java errors. Installing the latest JDK from Adoptium usually resolves it.

Step 3: Find the mods folder

Launch Minecraft once with the new profile. This creates the mods folder if it does not already exist. Then find it:

Windows: %appdata%\.minecraft\mods
macOS: ~/Library/Application Support/minecraft/mods
Linux: ~/.minecraft/mods

On Windows, press Win + R, paste %appdata%\.minecraft, and press Enter. The mods folder is inside.

Step 4: Download mods

Use CurseForge or Modrinth. Both are established platforms with version histories and dependency listings. Avoid sites that promise "premium mods free," require an installer, or ask for your Microsoft credentials — a mod is a .jar file you drop into a folder, nothing else.

CurseForge: each mod has a "Files" tab with builds listed by Minecraft version and loader.
Modrinth: each mod has a "Versions" tab with the same information.

Download the .jar matching your exact Minecraft version and loader. Do not rename it.

Step 5: Check dependencies

Many mods require other mods to run. The most common dependencies are:

Fabric API — required by nearly every Fabric mod.
Cloth Config API — required by mods with in-game settings screens.
Architectury API — required by mods that support both Fabric and Forge.
GeckoLib — required by mods with 3D animated entities.

The mod page lists these under "Relations" or "Dependencies." Missing one causes a crash on startup, not a warning.

Step 6: Launch and verify

Drop the .jar files in the mods folder. Launch Minecraft with the loader profile. If the game reaches the main menu, the mod loaded. Some mods add a Mods button to the main menu or a config screen accessible via Mod Menu (Fabric) or the built-in mod list (Forge/NeoForge).

If the game crashes on launch

Remove the last mod you added and try again. If it launches, that mod was the problem. If you added several at once, remove half and test. This is the binary search method and it is faster than removing mods one by one.

The crash report is in crash-reports inside your Minecraft folder. Open the most recent .txt. The top section titled ---- Minecraft Crash Report ---- contains the stack trace. Scroll through the at ... lines and skip anything starting with net.minecraft, java, sun, or the loader itself. The first line with a mod's package name is usually the culprit.

For a deeper walkthrough, see the crash log guide.

What about modpacks?

The CurseForge App and Modrinth App can install modpacks automatically, including the loader, dependencies, and configuration. This is the easier path if you want a pre-built experience rather than assembling mods yourself. For a lightweight setup with shaders, installing Fabric manually is faster and gives you more control.

Frequently asked questions

Can I install mods without a loader?

No. Mods require a loader. Bedrock add-ons are not the same thing — they are supported natively but much more limited in scope. Java mods always need Fabric, Forge, or NeoForge.

Do mods work on Bedrock?

No. Bedrock uses add-ons, which are not the same as Java mods. A Java mod will not load on Bedrock, and an add-on will not load on Java.

Can I install multiple loaders?

Not in the same instance. Each Minecraft profile runs one loader. You can create separate profiles for Fabric and Forge, but mods from one will not work in the other.

Where do I put resource packs and shaders if I use mods?

Resource packs go in resourcepacks, shaders in shaderpacks. Neither goes in mods. They are separate folders and separate systems.

Do I need to install mods on the server too?

It depends on the mod. Client-side mods (Sodium, Iris, Mouse Tweaks) do not need to be on the server. Server-side mods (Create, Mekanism) need to be installed on both client and server. The mod page lists its side.

Related guides

Fix "Mod Crashed" on Startup — full crash log walkthrough.

How to Install Shaders — Iris and OptiFine setup.

How to Choose a Minecraft Version — which version to play and why older versions still matter.