Lag and performance issues are some of the most common complaints from Minecraft server admins, and Lithium is one of the best free mods available to help fix that. It’s a Fabric mod that optimizes a wide range of vanilla game systems without changing gameplay, so players won’t notice anything different except a smoother experience. You do need to be running Fabric and make sure the version you install matches both your client and server.
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Installing Lithium
- Visit Modrinth and download the latest Lithium release that matches your server’s Minecraft and Fabric version.
- Open your server files through your panel’s File Manager, an SFTP program, or your PC’s file explorer.
- Navigate to the mods folder in your server’s main directory.
- Drop the Lithium
.jarfile into that folder. - Restart your server.
Configuring Lithium
The configuration file is located at:
config/lithium.propertiesThis file starts empty by design — you only add the options you want to override. Each optimization Lithium applies is controlled by a toggle in this file, so you can enable or disable specific systems to fit your server’s needs.
The full list of available config options is maintained on the Lithium GitHub page.
Troubleshooting
Server crashes on startup Confirm the Lithium version matches your Fabric loader and Minecraft version exactly. Version mismatches are the most common cause.
Conflicts with other mods If crashes only happen with Lithium alongside another mod, check the Lithium GitHub issues page for known incompatibilities.
Config changes not applying
Make sure you’re editing the correct lithium.properties file and that the syntax matches the format shown in the official documentation, then restart the server.