What Fabric Language Kotlin works with.
| Platform | Java Edition |
|---|---|
| Loaders | Fabric |
| Minecraft versions | 1.14.4, 1.16.5, 1.18.2, 1.19.2, 1.20.1, 1.21.1, 1.21.5, 1.21.8, 1.21.11, 26.1, 26.1.1, 26.1.2, 26.2 |
| Environment | Client, Server |
Fabric Language Kotlin is a library mod for Minecraft Java Edition. It carries the pieces that a Fabric mod written in the Kotlin programming language needs before it can start, and it does nothing else. Most players end up with it because a mod they wanted refused to load without it, not because they went looking for it.
What Fabric Language Kotlin does
Fabric mods are usually written in Java. A few are written in Kotlin instead, a different programming language that runs on the same platform but brings its own standard library along. Minecraft does not ship that library, so something has to supply it. This is that something. It bundles the Kotlin standard library and the common kotlinx libraries, and it registers a Kotlin adapter so Fabric Loader knows how to start a mod whose entry point is Kotlin code rather than Java code. That is the whole job.
- Bundles the Kotlin standard library and the common kotlinx libraries, so every Kotlin mod does not have to ship its own copy.
- Registers the Kotlin entry point adapter that Fabric Loader uses to start a Kotlin mod.
- Adds no blocks, items, mobs, recipes, keybinds, commands, config screen, or menu entry.
- Runs on the client and on a dedicated server, and belongs on whichever side is running the Kotlin mod.
Only a minority of Fabric mods are affected, so this is a fabric kotlin mod dependency rather than a universal one. On this site, Zoomify and Inventory Profiles Next are two whose current Fabric builds list it as required.
Version support and what actually breaks it
This is the unusual part, and it is the most useful thing to know before you download anything. Fabric Language Kotlin depends on Fabric Loader being present, not on a particular Minecraft version, so a single build works across the whole range. The current release, 1.13.13+kotlin.2.4.10 from 15 July 2026, declares support all the way from 1.14 to 26.2. The per-version tags on the project page exist so launchers and mod managers can match a file, not because separate builds exist underneath them.
- Loader: Fabric only. There is no Forge, NeoForge, or Quilt build, and nothing for Bedrock.
- Current release: 1.13.13+kotlin.2.4.10, a 7.7 MB jar published on 15 July 2026.
- That one file declares 47 Minecraft releases, from 1.14 through 26.2.
- 53 releases listed on Modrinth, tracking new Kotlin versions far more often than new Minecraft versions.
- Apache License 2.0, with the source on GitHub under FabricMC.
The honest limit is a mismatch rather than a version ceiling. A Kotlin mod is built against a specific release of this library and declares a minimum it will accept, so an old copy left in the mods folder from last year is a far more common cause of a startup crash than a new Minecraft drop is. When a mod complains, update this library rather than downgrading the game.
How to install Fabric Language Kotlin
- 1.Install Fabric Loader for the Minecraft version you play, then launch the game once so the mods folder is created.
- 2.Open the Modrinth project page and pick the version tag matching your Minecraft version, then download the jar.
- 3.Put the jar in the mods folder alongside the mod that asked for it. Do not unzip it.
- 4.Start Minecraft on the Fabric profile. If the mod that needed it now loads, the library is doing its job.
The folder locations and launcher steps are the same as for any other Fabric mod, and our guide to installing Minecraft mods on Java covers them in full. For a server, the jar goes in the server's own mods folder, not the one on your PC. Do not go looking for a separate fabric language kotlin download anywhere else, because every build comes from the same Modrinth page linked above.
Downloading and adding Fabric Language Kotlin to the mods folder
Questions about Fabric Language Kotlin.
5 questions
Do I need Fabric Language Kotlin if I only play with mods and don't make them?
Only if one of your mods asks for it. It is a dependency, not something you install for its own sake. Most Fabric mods are written in Java and never touch it. If a mod you want lists it as a required dependency, you need it. If none of them do, adding it does nothing at all.
Why does a mod I installed require Fabric Language Kotlin?
Because that mod was written in Kotlin rather than Java. Kotlin code needs its own standard library and a special entry point adapter to start under Fabric Loader, and Minecraft ships neither. This library supplies both, once, for every Kotlin mod in the folder. Without it, Fabric Loader has no way to launch the mod and refuses to start.
Which Minecraft version does Fabric Language Kotlin support?
Effectively all of them on Fabric. The current release, 1.13.13+kotlin.2.4.10, declares 47 Minecraft releases from 1.14 through 26.2 in a single file. The library depends on Fabric Loader being present rather than on a particular game version, so the version tags on the download page are there for launchers to match rather than marking separate builds.
Does Fabric Language Kotlin work on a Minecraft server?
Yes. It runs on both the client and a dedicated server, and it belongs on whichever side is running the Kotlin mod. A server-side mod written in Kotlin needs this jar in the server's mods folder. A client-side one needs it on your PC. If a mod runs on both sides, install the library on both sides too.
Is Fabric Language Kotlin the same as Fabric API?
No, and you may well need both. Fabric API is the shared toolkit that most Fabric mods build against, regardless of language. Fabric Language Kotlin only handles the Kotlin runtime and entry point adapter. Neither replaces the other, and neither replaces Fabric Loader, which is the piece the launcher installs first.
