For its first years Lithium was a Fabric-only mod, and Forge players got by with community ports. That changed in autumn 2024, when CaffeineMC began publishing official NeoForge builds next to the Fabric ones. This page mixes both eras, so the file you pick decides what you actually get.
The three files, one by one
- lithium-neoforge-0.14.4 for 1.21.4. An official CaffeineMC release for NeoForge, built from the same source as the Fabric original. It gets the same optimizations and the same configuration file. Version 0.14.4 was a NeoForge-only fix release from December 2024, which is why the Fabric list skips from 0.14.3 to 0.14.5.
- lithium-mc1.15.2-forge-0.4.6-rc3 for 1.15.2. Another unofficial port, based on the 0.4 code line of the time. It depends on the Mixin library, which Forge 1.15.2 only includes from build 31.2.44 onward; on older Forge builds people added MixinBootstrap to load it.
A quick way to tell the official file from the ports: CaffeineMC names its jars lithium-neoforge or lithium-fabric followed by the version and the Minecraft version. Anything else on this page is a third-party build.
The old 1.15.2 port is frozen. Nobody updates it, and with a release-candidate build you should test on a copy of your world before trusting it with a long-running save. We keep it because 1.15.2 Forge packs still circulate.
NeoForge is not Forge
The official file needs NeoForge, the fork that split from Forge in 2023. It will not load in a Forge instance, even on the same Minecraft version. Check the loader name in your launcher profile before you download.
For classic Forge between 1.18.2 and 1.20.x, the answer is Canary. It is an unofficial fork of Lithium for Forge, maintained by AbdElAziz rather than CaffeineMC, and it carries the same idea over: faster game logic without changing how the game plays. Use one or the other, never both in the same instance. Canary is built from Lithium’s code, so the two would try to patch the same parts of the game.
Setting up the NeoForge build
Install NeoForge for 1.21.4, copy lithium-neoforge-0.14.4 into the mods folder, and start the game. Lithium has no menu of its own, so look for it in the mod list on the title screen to confirm it loaded. For a dedicated server, run the same NeoForge installer with Install server selected and put the jar into the server’s mods folder.
The rules match the Fabric version. It works on a dedicated NeoForge server without clients needing it, and on a client without the server needing it. It creates config/lithium.properties on first launch; leave it empty unless you are chasing a conflict, since an empty file means every stable optimization is on. NeoForge has its own list of option names in the CaffeineMC documentation, which differs slightly from the Fabric list.
Building a Forge-side performance set
Lithium makes the world tick faster; it does nothing for rendering. On NeoForge 1.21.4 the natural partner is the official NeoForge build of Sodium, which you will find on our Sodium for Forge and NeoForge page. Between them the two cover the tick and the frame.
Running something much older? On 1.12.2 FoamFix reduces memory use in large Forge modpacks, a different bottleneck from the one Lithium works on.
Still on the loader step? The Forge page covers installing the loader itself.