How to Make a Modpack in Modrinth

What is Modrinth?

Modrinth is an open-source platform and desktop launcher for Minecraft mods, modpacks, shaders, resource packs, and data packs. The Modrinth App handles the parts that used to be manual: it installs the modloader for you, filters every project to your exact Minecraft version, pulls in dependencies automatically, and keeps each pack in its own isolated instance so a broken mod can never affect your other worlds.

• Free and open source, with no download gates or ad redirects
• Automatic dependency installs and strict version compatibility filtering
• Supports Fabric, NeoForge, Forge, and Quilt
• One-click export and import of packs as .mrpack files
• Can also import CurseForge packs from a zip file

Official site: modrinth.com

Before you start

• A paid Minecraft: Java Edition account. The app signs in with Microsoft and verifies ownership. Bedrock, PS, Xbox, and Switch versions cannot use Java modpacks at all.
• Windows, macOS, or Linux. The app ships Java with each instance, so you do not need to install a JDK yourself.
• Free RAM. 8 GB of system memory is enough for a small pack; 16 GB is comfortable for 100+ mods with shaders.
• A few GB of disk space. Each instance keeps its own mods, assets, and worlds, so packs do not share files.
• A decision on version and loader. Changing either after you have installed 40 mods means redoing most of the work — see the next section.

Choosing a Minecraft version and modloader

Every mod is built for one Minecraft version and one loader. Mixing them is the single most common reason a first pack refuses to launch, so pick the combination your must-have mods actually support and build around it. If you are unsure, check the two or three mods you care about most and use whichever version they all share.

A practical tip: stay one or two Minecraft releases behind the newest one. Mod authors need weeks to update, and the version right after a big release usually has the thinnest selection.

Step 1. Download & install the Modrinth App

Grab the app from modrinth.com/app and run the installer. If Windows SmartScreen shows a warning, choose More info → Run anyway; the installer is unsigned on some builds. Keep the default install path unless you want instances on a different drive, which you can also change later in Settings.

Step 2. Sign in with your Microsoft account

Open the app and sign in with the Microsoft account that owns Java Edition. The login opens in a browser window and returns to the app when it finishes. You can add several accounts and switch between them from the avatar menu, which is handy if you play on a family account.

Step 3. Create the modpack

Click Create new instance on the home screen, give the pack a name you will recognise later, then set the Minecraft version and modloader you chose above. Modrinth downloads the loader for you. Open the Library tab and click your new pack to open its page — do not press Play yet, since launching once before adding mods just wastes a few minutes.

Step 4. Add mods & shaders

Click Install content inside the instance. The search is already filtered to your version and loader, and the tabs switch between Mods, Resource Packs, Data Packs, and Shaders. When a mod needs a library, Modrinth installs it with one prompt — accept it, because declining leaves the pack in a state that crashes on launch.

For shaders you need a shader loader first: Iris on Fabric or Quilt, Oculus on Forge. Install that, then install shader packs from the Shaders tab and enable one in Video Settings → Shaders once the game is running. Add mods in small batches and launch between batches; finding the one bad mod out of five is far easier than out of fifty.

Starter mods worth adding first

Install performance and quality-of-life mods before content mods. They cost almost nothing to run, they rarely conflict, and they make the frame rate headroom for everything you add afterwards.

Step 5. Allocate RAM and launch

Open the instance's options and set memory before the first launch of a large pack. Roughly 4 GB suits 20 to 60 mods, and 6 to 8 GB covers 100+ mods or shaders. More is not better — oversized heaps make garbage collection pauses longer, and Minecraft rarely benefits past 8 GB. Keep at least a third of your system RAM free for the OS.

Then press Play. The first launch is slow because assets and the loader are still downloading. If it crashes, open the logs from the instance page — the last few lines almost always name the mod at fault.

Step 6. Export and share your modpack

This is the part most tutorials skip. Open the instance, choose Export, tick the files you want bundled, and save the .mrpack file. It is only a few kilobytes because it stores download links and exact mod versions rather than the jars themselves.

• How friends install it: send them the file, then they use Add instance → From file in their own Modrinth App. Everyone ends up on identical mod versions, which is what stops the classic "works on my machine" multiplayer mismatch.
• Manually added jars: mods you dropped into the folder yourself have no download link, so include them as overrides during export or tell people to add them by hand.
• Re-export after changes: an .mrpack is a snapshot. Adding a mod later does not update files you already shared.
• Publishing publicly: you can upload the pack as a project on modrinth.com, but every bundled mod must permit redistribution — check each licence first.

Using your modpack on a server

An .mrpack is a client pack, so you cannot upload it to a host and expect it to run. Set the server up separately with the same Minecraft version and the same loader, then copy across only the mods that have a server side. Client-only mods — shaders, minimaps, Mod Menu, most UI tweaks — will crash a server or simply do nothing.

Every player still needs the client pack installed, and version mismatches between client and server show up as a rejected connection rather than a clear error. Our server RAM calculator helps size the host once you know how many mods and players you are running.

Updating without breaking things

• Duplicate before big changes. Right-click the instance and duplicate it, then experiment on the copy. Reverting a broken pack takes seconds this way.
• Back up worlds separately. Copy the saves folder out of the instance before adding or removing content mods. Removed mods can leave a world unloadable.
• Update mods in the Installed tab and launch once before touching a real world, so a bad update never lands mid-session.
• Jumping Minecraft versions is a rebuild, not an update. Some mods will not have a build for the new version. Create a fresh instance and re-add mods rather than forcing the old one.

Troubleshooting common problems

When nothing obvious stands out, halve the pack: disable half the mods, launch, and repeat on whichever half still fails. Four or five launches narrows 100 mods down to the culprit.

Frequently asked questions