A modpack bundles a curated set of mods, plus configs and often a shader or resource pack, into one install that only a matching launcher can read correctly. This guide covers the four common Java Edition launchers built to read modpacks, the CurseForge app, the Modrinth App, Prism Launcher, and the ATLauncher, plus a manual install for a .mrpack file or a CurseForge zip when none of those fit. Browse our modpack library for packs already tagged by Minecraft version and loader. Bedrock Edition doesn't have modpacks in this sense; its behavior packs and add-ons install a different way, covered in our mods and add-ons guide.
How to install a modpack with the CurseForge app
The CurseForge app is Overwolf's launcher and it remains the largest single home for Minecraft modpacks, including packs that never post anywhere else. Open the app, switch to the Minecraft section, search for the pack by name, and click Install. The app reads the pack's manifest, downloads the matching Minecraft version and mod loader automatically, and adds a Play button once the download finishes. A well-known example is RLCraft, one of many packs that ships only through CurseForge with no official Modrinth listing or manual mirror.
How to add a modpack to Minecraft with the Modrinth App
The Modrinth App is Modrinth's own launcher and the natural choice for a pack that's only listed there, or for a Fabric-first pack like Fabulously Optimized. Search or browse in the app, open the pack's page, and click Install; pick a specific pack version first if more than one is offered. The app creates its own instance with the correct loader and Minecraft version already set, so there's nothing to configure by hand before pressing Play.
How to install a modpack with Prism Launcher
Prism Launcher is a free, open-source, community-run launcher that reads packs from both CurseForge and Modrinth without needing an account on either. Choose Add Instance, pick Import from CurseForge or Import from Modrinth, search for the pack, such as Cobbleverse or Vanilla Perfected, and select Create Instance. Prism keeps every pack in its own isolated instance, which makes it a strong option for running several large packs side by side without one pack's mods leaking into another.
How to install a modpack with the ATLauncher
The ATLauncher curates its own pack list alongside third-party packs and, like Prism, needs no CurseForge or Modrinth login. Open the Packs tab, search for the pack, click its tile, and choose Install; the launcher downloads the correct loader and version and creates a dedicated instance automatically. It's a solid alternative to the two official apps for a pack such as Completecraft, which ATLauncher's own catalog tends to keep well up to date.
Install a modpack manually from a .mrpack file or a CurseForge zip
Not every pack needs its host's own app. A .mrpack file, Modrinth's packaging format, opens directly through Prism Launcher, the ATLauncher, or the Modrinth App itself; use each launcher's Import or Add Instance option and point it at the downloaded file. That covers how to install minecraft modpacks whenever a pack's own listing offers only a raw file instead of a browsable catalog entry.
A CurseForge-format zip is built differently. It contains a manifest.json describing the exact Minecraft version, mod loader, and mod list, plus an overrides folder with configs and any files the loader can't fetch on its own. Installing one by hand looks like this:
- 1.Create a new instance in Prism Launcher, the ATLauncher, or MultiMC set to the loader and Minecraft version named in manifest.json.
- 2.Download every mod listed in manifest.json from its Modrinth or CurseForge project page and drop the .jar files into that instance's mods folder.
- 3.Copy everything inside the zip's overrides folder into the instance's root folder, merging it with the existing config and mods folders.
- 4.Launch the instance once to confirm the mod list loads without errors.
Most players never need those four steps by hand. Prism Launcher and the ATLauncher can both import a CurseForge zip directly and unpack it automatically, which is how to install a modpack without CurseForge's own app when a zip is all that's available.
How much RAM to allocate for a modpack
Every modpack launcher lets you set how much RAM the Minecraft instance can use, usually in the instance's settings under Java or Memory. The launcher's own default, often two to four gigabytes, is tuned for vanilla Minecraft, and a large pack with hundreds of mods routinely needs more just to finish loading, let alone run smoothly. A crash, black screen, or out-of-memory error on the very first launch is the single most common modpack problem, and low RAM is the usual cause.
More isn't automatically better. Handing Minecraft most of the system's memory starves the operating system and every other running app, and a Java heap that's too large can make the game's periodic garbage collection pauses longer and more noticeable instead of preventing them. Check whether the pack's own page lists a recommended allocation, start there, and leave several gigabytes of RAM free for the rest of the system. If a pack keeps crashing after a reasonable increase, the beginner troubleshooting checklist covers the other common causes.
Playing a modpack with friends
Multiplayer only works when every player is running the identical modpack version; a mismatched mod list or even a one-version difference is the most common reason a group can't connect, or one player sees missing blocks and items. Confirm everyone installed the same pack version before troubleshooting anything else. Hosting a server needs a separate download for most packs: the server-side files usually strip client-only mods, like shaders and sound packs, and add a couple of server-only ones, and they're published apart from the regular client download on the pack's own page. Grab that server package rather than trying to run the client install on a server.
Frequently asked questions
How do I install Better Minecraft without CurseForge?
Check the pack's own listing first. Many packs that started on CurseForge, including large ones like Better Minecraft, also publish on Modrinth or as a plain .mrpack file, in which case the Modrinth App, Prism Launcher, or the ATLauncher install it the same way as any other pack. When a pack genuinely has no listing anywhere else, the CurseForge app is the only legitimate way to get it. We don't recommend repackaged copies or modified launchers that claim to unlock it another way; their files come from an unclear source, which is exactly what this guide is trying to help a reader avoid.
How much RAM should I allocate for a modpack?
Start with the pack's own recommended amount if it lists one; otherwise, four to six gigabytes covers most mid-sized packs, and very large packs may need eight or more. Set it in the launcher's instance settings, and leave enough of the system's total RAM free that the operating system and launcher itself still run comfortably. See the RAM allocation section above for why more isn't always the fix.
Does everyone need the same modpack version to play together?
Yes. Minecraft multiplayer expects every connected player to have matching mods, matching mod versions, and the same resource or data content those mods add, so a different pack version between players causes disconnects, missing content, or outright crashes. Update or roll back everyone to the same pack version before joining the same world.
Why does my modpack crash on the first launch?
Low RAM allocation is the most common cause, followed by an interrupted or partial download and a Java version mismatch with the pack's required loader. Reinstalling through the launcher's own repair or verify option, confirming the RAM setting matches what the pack recommends, and checking the beginner troubleshooting checklist for Java version issues cover most first-launch failures.
