How to install a Minecraft mod

Installing your first Minecraft mod is easier than it looks. A mod installs as one file, a .jar. It loads only when three things agree. You are on Java Edition. The profile is the loader that file was built for. The Minecraft version is the one named on the download. A jar that misses any of those sits in a folder the game never reads. Once your first mod loads, the Minecraft guides cover loaders, performance mods and servers.

I play Minecraft 1.21.1 on NeoForge: Create 6.0.10, Aeronautics 1.3.2 (needs Sable), plus the rest of Create Aeronautics. We share the instance through the Modrinth App. Create 6.0.10 for 1.21.1 is a NeoForge file (release tag mc1.21.1-6.0.10). Best Minecraft mods is which jars are worth adding. Looking for which mods to add? See the best Minecraft mods. Here’s how to install one.

Java Edition, not Bedrock

These steps are for Minecraft: Java Edition, the copy you launch from the Minecraft Launcher, with worlds stored under a folder named .minecraft. Bedrock, the edition on consoles, phones, and the store app that comes with Windows, uses add-ons and behavior packs. A Java jar does not go there. A resource pack is a different file.

The file names the loader

A mod does not run on its own. A loader sits between it and the game. The download page names the loader. CurseForge’s Java install guide, updated in October 2025, lists four: Forge, Fabric, NeoForge, and Quilt. The file has to match that name. A Fabric jar in a Forge profile does not load. A Forge jar and a NeoForge jar are different files, even when the mod has the same name.

Our pack already named NeoForge 1.21.1. Sodium and Iris also ship NeoForge files for that version. OptiFine on this pack is a crash path — OptiFine vs Sodium.

You can keep more than one profile. One mods folder cannot serve two of them.

Most Fabric mods also need Fabric API, a second jar from Modrinth or CurseForge, for the same Minecraft version. Fabric’s own install guide says the majority of its mods require that file. Quilt’s equivalent is Quilted Fabric API. The mod page’s relations or description names anything else required. Those files go in the same folder as the mod. Create 6.0.10 for 1.21.1 does not list a separate required dependency on the official release note. Aeronautics 1.3.2 needs Sable.

Install the loader for that version

If you are joining our pack, open the Modrinth App share link and accept the invite. The app creates the instance with the right loader, version, and mods. You can skip the rest of this section.

If you are installing one jar yourself: run the plain game once on the version the mod supports, then close it. That download is what the installer expects to find. Then get the installer from the loader’s own site. Fabric is fabricmc.net. Forge is minecraftforge.net. NeoForge is neoforged.net. Quilt is quiltmc.org. A page that wraps the installer in a survey, or asks you to run a different downloader, is not that site.

Run the installer. Choose the client, and the same Minecraft version. It adds a profile to the Minecraft Launcher. Open the launcher, pick that profile in the dropdown beside Play, and launch it once before you add anything. The title screen should show the loader’s name. If it still shows the plain version, the dropdown is on the vanilla profile, and the folder work below will look like it did nothing.

Put the jar in the folder that profile uses

The official launcher keeps one mods folder.

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

Paste the Windows path into File Explorer’s address bar. On a Mac, Finder’s Go menu has Go to Folder. If mods is not there, launch the loader profile once, or make the folder yourself and name it mods, in lowercase. Once that profile is running, the Mods button on the title screen opens the folder that profile reads.

Download the jar from CurseForge or Modrinth with the version filter and the loader filter both set. Leave the jar whole. Drag it into that folder, and drag each required dependency in with it.

A CurseForge app profile, a Modrinth app instance, or a Prism instance keeps a different mods folder inside that instance. A jar placed in .minecraft\mods does not reach them. Add the file from the instance’s own mods list, or open that instance’s folder and use the mods directory inside it. That is the folder I would open for Create Aeronautics.

Before you press Play

Quick check before you hit Play:

The download is still a .jar, for this Minecraft version The profile I will launch is the loader named on that file Every required dependency is in the same folder

The mod, the loader and the game version all have to match.

Launch the loader profile. On the title screen, open Mods. The file should be listed.

The official launcher has one .minecraft folder, so it has one mods folder. A second pack in that same folder mixes two loaders, or two Minecraft versions. A large mod wants its own instance for this reason. The CurseForge app and the Modrinth App make a separate folder per profile. On the official launcher, a second setup means a second game directory, or you take the jars out before you switch. Choosing a profile does not sort the folder.

Copy the world before you swap loaders or update a content mod — keep a modded world from breaking. Heap is a different slider: allocate RAM.

When the mod is missing or the game closes

The profile is still vanilla, or it is a different loader than the file. Pick the profile the installer added. For our pack, that is the Modrinth NeoForge row, not Latest Release.

The version does not match. A jar built for one Minecraft version does not load on another. Fabric’s install notes use the split directly: a mod that ran on 1.21.8 may not run on 1.21.11. The number on the file, the loader, and the profile have to be the same number. Create 6.0.10 is 1.21.1.

A required jar is missing. Fabric API is the common one on Fabric. Sable is the one Aeronautics names. The message often names the missing file. Put that file in the same folder.

The jar was unzipped, so the folder holds loose files instead of one .jar.

An older jar is still in the folder. Guides that install Forge, NeoForge, and Fabric treat exit code 1 as that mismatch. Take out the last jar you added and launch again. If the instance will not boot, remove the last mod you added. For the official launcher, the log is .minecraft\logs\latest.log.

A line that says OutOfMemoryError: Java heap space is a memory limit, not a bad jar. A JNI error is the other split. The Java that profile is using does not match the game version. The official launcher and the loader installer are what should supply that Java.

Once the menu holds, add the next jar. Performance mods such as Sodium and Lithium belong in front of a pile of content mods, and the settings around them are in how to increase FPS. To take a mod out, delete its jar. To update one, replace that jar with the new file for the same loader and the same Minecraft version.

Related: Minecraft guides, What Minecraft server hosting is, PC builds, Java snapshot news.

Common questions

Can you install mods on Minecraft Bedrock?

Not the same way. These steps are for Java Edition, which runs from the Minecraft Launcher. Bedrock on consoles, phones and the Windows store app uses add-ons instead of a mods folder.

Can I use Fabric and NeoForge mods together?

No. Every mod has to match the loader your profile uses. If you want both, make a separate profile and mods folder for each loader.

Should I unzip a Minecraft mod?

No. Leave the mod as a .jar file and drop it straight into your mods folder. Unzipping it breaks the mod and the loader won't read it.

Where is the Minecraft mods folder?

On Windows, paste %appdata%\.minecraft\mods into File Explorer. On Mac it's ~/Library/Application Support/minecraft/mods, and on Linux it's ~/.minecraft/mods. Modrinth instances have their own separate mods folder.

Why isn't my Minecraft mod showing up?

Most likely you launched the vanilla profile, or the mod is for a different loader or Minecraft version. Launch the profile your loader installer created, then check the Mods button on the title screen.