Frequently Asked Questions (from users)

This is the simplified version! For technical answers, see the "expert mode" supplement of the FAQ.

For most cases, the answer is “snapshot 18w43b and above, releases 1.14 and above”.

There exist ways to run Fabric with older versions - modded or vanilla, but they're currently non-trivial or unofficial - see the expert FAQ for more details.

By 'fabric' it is referring to the Fabric API mod.

Fabric doesn't come with a mod menu built-in. There's a mod called Mod Menu that adds it. Some mods integrate with Mod Menu and add in-game configuration screens. Click on the “Mods” button and select the mod you want to configure; if the mod integrates with Mod Menu, you'll see a “Settings” button on the top-right.

They are most often on CurseForge or Modrinth. Some mod authors may upload their mods to other sites such as GitHub, GitLab or their own site. See adding mods for more information.

Yes. Published Fabric modpacks can be found on websites such as the following:

• CurseForge
• Modrinth
• Technic
• FTB
• ATLauncher

Sometimes modpacks may be distributed as exports in the CurseForge format, Modrinth format, MultiMC format, or another format.

You can use launchers to browse for or install modpacks:

• ATLauncher
• CurseForge App
• FTB App
• GDLauncher
• Modrinth App
• MultiMC
• Prism Launcher
• Technic Launcher

Some modpacks also allow you to download a “server” pack to install it in Minecraft Launcher.

If someone has shared their modpack export, you can import it into some of these launchers.

As of August 2023, the following launchers are available to export instances as a modpack:

• Official Launcher - an installer is available on Fabric's download page. A guide is available
• MultiMC - a guide is available for Windows, and for macOS; there is an “Install Fabric” button to easily install Fabric loader.
• Prism Launcher
• CurseForge App - supports Fabric, just choose “Fabric” then select a version when creating a modpack.
• GDLauncher - supports Fabric, just choose “Fabric” then select a version when creating an instance. A guide is available for Windows and Linux
• ATLauncher - supports Fabric download and installation.
• Modrinth App
• HMCL - supports Fabric download and installation, including sources from mirror websites.

As of August 2023, the following launchers are available for this:

• MCUpdater - guide
• Technic (Solder) - guide
• ATLauncher - guide
• MultiMC
• Prism Launcher
• CurseForge App
• GDLauncher
• Modrinth App
• Packwiz (CLI)
• Moddermore (website)

The default, vanilla Minecraft Launcher is oftentimes not enough to manage a lot of modded instances. For that reason, alternative Minecraft launchers were created.

Advantages of using an alternative launcher:

• Easily install Fabric
• Built-in mod downloading and updating
• Automatically download mod dependencies
• Built-in modpack downloading and updating
• Allow you to export and import modpacks
• Designed specifically for modded Minecraft
• Automatically create separate folders for instances which helps you separate your saves
• May launch faster

No, and it is unlikely to be officially supported. This is due to many core differences between Fabric and Bukkit/Spigot/Paper.

If you really want to run plugins on Fabric, you can try the unofficial Cardboard mod, but beware that it is incompatible with many mods and doesn't support the complete Bukkit/Spigot/Paper API.

No. Forge mods must run on Forge, and Fabric mods must run on Fabric. You cannot mix mods.

• Fabric does not work on top of Forge.
• It is theoretically possible to create a way to do so - that is to say, there are no known major technical obstacles in accomplishing such.

The Fabric development team does not consider Forge interoperability a high-priority goal, as our focus in our limited time dedicated to the project is on supporting the Fabric community and its developers and users.

There is, however, Sinytra Connector (GitHub, CuseForge, Modrinth), a project which aims to allow running Fabric mods on the Forge mod loader. It is not officially supported or recommended.

Consider using alternatives to OptiFine, as unofficial mods such as OptiFabric may not be compatible with your mods.

In particular, OptiFabric 1.14.25 is currently incompatible with Architectury API and Replay Mod.

This is because OptiFabric 1.13.25 and below are incompatible with Fabric Loader 0.15.0 and above. This is why you'll see java.lang.NoClassDefFoundError: net/fabricmc/tinyremapper/IMappingProvider in your log. You'll need to use Fabric Loader 0.14.25.

If you're using OptiFabric 1.13.25 for compatibility with Architectury, you'll need to use Fabric API 0.85.0 as it was incompatible with Fabric API 0.86.0 and above.

OptiFabric is currently incompatible with Fabric API 0.77.0. You'll need to use Fabric API 0.76.1.

Fabric's rendering patches, while as minimally invasive as possible, make some assumptions about the data format used internally by the vanilla rendering system. Shaders break this assumption, so things go awry. Workarounds do exist and are implemented by the most recent versions of said unofficial mods.

DO NOT downgrade Fabric API as a workaround for this. It's a bad idea.

This is because Sodium does not yet support the Fabric Rendering API which some mods such as Continuity use. This is why you'll see java.lang.NullPointerException: Cannot invoke “net.fabricmc.fabric.api.renderer.v1.Renderer.meshBuilder()” because the return value of “net.fabricmc.fabric.api.renderer.v1.RendererAccess.getRenderer()” is null in your log. Add the Indium mod to resolve this.

This is most likely because a mod requires Indium.

Not at the moment. Sponge does not yet have a ready API or a working implementation for 1.14, the Minecraft version that Fabric runs on.