How to Reduce Lag on a FabricMC Server

Unlike SpigotMC and PaperMC, FabricMC does not come with any optimizations to the Vanilla server to improve server performance. FabricMC is just the mod layer for your server, similar to how Bukkit is just the plugin layer that Spigot and Paper build off of.

However, there are some mods that you can install on your Fabric server to improve performance. Some of these mods include Lithium, Phosphor, and Hydrogen. Each of these mods focuses on tweaking different parts of the server to improve overall performance.

Important Reminder: These mods may not be compatible with the mods already installed on your server. Should you run into any issues after installing one of these mods, we recommend that you remove it.
Mod Description Supported Versions
Lithium Lithium focuses more on optimizing tick processes and mob behaviors, improving AIs, and changing data structures within the server to be more optimized, which can lead to an average of 45% improvement in server TPS. 1.15-1.18.2
Phosphor Phosphor focuses on optimizing the server's lighting engine, which decreases the time taken to generate or load chunks, helping to reduce overall stuttering when traversing the world. 1.15-1.18.2
FerriteCore FerriteCore primarily focuses on reducing memory usage. Usage of the mod can reduce memory usage by up to 45%. 1.16-1.18.2
Starlight Starlight is a mod similar to Phosphor, but instead of simply optimizing the lighting engine, it was completely rewritten. Due to this, it is incompatible with Phosphor. 1.17-1.18.2
ServerCore ServerCore is a mod that optimizes the Minecraft server. This includes optimizations to entities, mob spawning, and chunk ticking. 1.17.1-1.18.2
Hydrogen Hydrogen focuses on reducing memory usage and improving the TPS of the server. Both of these can be very helpful as modded servers are much more resource-intensive. 1.16-1.17


If you're looking to improve client-side performance, Sodium is a mod made by the developer of Lithium, Phosphor, and Hydrogen to help improve client-side performance in a similar vein to OptiFine. However, Sodium may have some compatibility issues with specific mods that use the Fabric Rendering API. Lithium and Phosphor can also be installed onto your client to improve client-side performance as well.

Installing these mods on your server follows the normal Fabric mod installation process.

Aside from installing optimization mods, you can take a look at our other guides on Reducing Lag.

If you require any further assistance, please contact our support at: https://shockbyte.com/billing/submitticket.php

Mitchell Smith

Managing Director @ Shockbyte

  • fabric, fabricmc, mod, Modded, modded server, lag, reduce lag, fix lag
  • 30 Users Found This Useful
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