MultiMC

MultiMC does not support automatic updates by default. However, FO has developed a custom MultiMC pack to perform updates automatically. Read more about the MultiMC auto-updating pack

You may also want to use one of the other launchers supported by FO, which offer easier installation, updates and mod management.

Automatic Updates (recommended)

1. Download and install Java 21

2. Download FO's MultiMC pack for your preferred Minecraft version from GitHub Releases:

   • 1.21.5

   • 1.21.4

   • 1.21.1

   • 1.20.6

   • 1.19.4

   • 1.18.2

   • 1.17.1

   • 1.16.5

3. If you do not want the latest version, you can find older ones in GitHub Releases

4. Open MultiMC

5. Drag the zip file and drop it inside of MultiMC's window. A window should pop up

6. Click OK in that window. Something should happen

7. Double-click on that window. The download should start

8. If you are asked to download a mod manually:

   1. Open the given address in your browser. The mod's page should open up

   2. Click on Cancel Launch

   3. Click on Download. A jar file should be downloaded

   4. Go back to MultiMC

   5. Click on the instance you just created

   6. Click on View Mods

   7. Drag the mod you downloaded in step 8.3 and drop it in the mod list

9. Click on Launch. Minecraft should open up

10. If you can see Fabulously Optimized in the bottom-right corner, you're done!

How Does It Work?

The MultiMC auto-updating pack launches packwiz every time it is opened. packwiz is a mod handling tool which will add and update any missing FO mods indicated in a pack.toml file.

Since the update checker runs on every launch, you'll get a skippable error if you play offline. The updater only manages FO's mods, not the mods added manually. The updater does not work across Minecraft versions, so you'll need to install it again every time.

MultiMC does not natively support automatic updates of packs: see issue #2640 and issue #3037. FO chose to use packwiz because it is also used for the vanilla installer.

Before FO 6.0.0, the MultiMC auto-updating pack was distributed on CurseForge, but that has changed for the following reasons:

• CurseForge's UI for downloading the MultiMC auto-updating pack became confusing

• The pack had to be re-uploaded on every update, which was often unnecessary

• The pack's downloads via CurseForge might not support FO as previously thought
• The pack proved to have unexpected issues that do not exist with other launchers

Easier Installation

1. Download and install Java 21
2. In MultiMC, click on Add Instance
3. Click on the Modrinth tab on the left

4. Click on Fabulously Optimized

5. If you do not want the latest version of FO, select the version you want from the dropdown

6. Click on OK. Once installed, something should happen

7. Double-click on the icon. Minecraft should open up

8. If you can see Fabulously Optimized in the bottom-right corner, you're done!