Server performance mods for Fabric and NeoForge that support Minecraft 26.2

Where a modded server loses its time

A server has 50 milliseconds per tick for mobs, crops, redstone, light, terrain and the packets to every player. Each performance mod rewrites one part of that work so it costs less time or memory, which is why one mod rarely fixes everything and five mods on the same part help no more than one.

Before any of this, find out which row your lag lives in. A server that stalls because players explore needs pre-generated terrain far more than a physics mod, and a server short on memory needs a bigger heap before FerriteCore can make a real difference.

The mods with a stable 26.2 build

Checked on each mod's Modrinth page on 14 September 2026, counting stable releases only. On Forge 26.2 only spark and Chunky had builds; none of the others did.

Several names from older lists are missing on purpose. Some have alpha builds for 26.2 and nothing stable yet, others stopped at an earlier version or were archived. When 26.3 comes out, expect the same gap again: check each mod's page for your exact version before you move the server to it.

Which ones combine, and which ones clash

Most of these mods touch different parts of the server and sit together without trouble. The exception is Moonrise, because it replaces whole systems that other mods only patch. Its own compatibility notes and mod metadata say this:

• Moonrise with Lithium or FerriteCore: works. Moonrise switches off the parts of Lithium and FerriteCore that overlap with its own changes. Its authors check that for each release, so update these mods together rather than one on its own.
• Moonrise with ScalableLux: Moonrise already contains a light engine from the Starlight family, and ScalableLux presents itself to the loader as Starlight. Moonrise declares Starlight incompatible, so Fabric Loader will not start a server with both.
• Moonrise with C2ME: incompatible. C2ME rewrites the chunk system that Moonrise replaces wholesale, and for 26.2 it only has alpha builds anyway.
• Krypton: its author calls it a work in progress and tests it against Fabric API and Lithium. If connections misbehave, take it out first.

Pick one of the first two rows, not both. spark goes on every setup, because you measure with it.

The three that change something players might notice

Lithium, FerriteCore, ScalableLux and Moonrise aim at exact vanilla behaviour; Lithium is even allowed in official Minecraft speedrunning. Three others trade a little of that for speed.

Alternate Current

Vanilla redstone dust updates its neighbours in an order that depends on where the wire sits in the world, which makes that order hard to predict. Alternate Current calculates the whole wire network first and then updates in the direction the power flows. Almost every build keeps working, but a machine that relies on the vanilla order can behave differently, so test the big ones before and after.

Clumps

Clumps merges XP orbs lying close together into one entity and lets players pick them up the moment they touch them. An XP farm stops spawning hundreds of separate orbs, which is the whole point, but the pickup feels different from vanilla. On 1.17 and newer it only has to be on the server.

ServerCore

ServerCore ships in a cautious state. Two of its optimisations are on from the start, reduce-sync-loads and cache-ticking-chunks, and the first one means held maps only draw chunks that are loaded. Everything heavier is off until you enable it in config/servercore/config.yml:

Most of those settings reload with servercore reload in the console; servercore status shows what the dynamic settings are doing right now, and mobcaps shows the mob caps per player. The second file, optimizations.yml, only takes effect after a restart.

What players have to install

Nothing from this list. Modrinth marks ServerCore and Alternate Current as server only, and the others as optional on the player's side. Lithium states outright that clients can join without it. FerriteCore suggests both sides, but only because it also saves memory in the player's own game; joining works without it. A player who wants smoother frame rates on their own computer can add a rendering mod such as Sodium, which the server never needs.

Unlike content mods, adding or removing these never changes the list players need, so you can test them without sending anyone a new pack. The guide to joining a modded server covers the mods players do share.

One detail for Fabric: Modrinth lists no Fabric API dependency for the 26.2 files of Lithium, FerriteCore, ScalableLux, Moonrise or spark, but Clumps and Chunky require it. Install those two from the Mods tab and the catalog fetches Fabric API along with them.

Installing them from the Mods tab

1. 1

   Set an exact version

   On the Settings tab, check Server type and the Minecraft version field under Server software. The catalog searches for exactly that loader and version, so a server on Fabric 26.2 only sees files built for Fabric 26.2.

2. 2

   Search the verified catalog

   Open the Mods tab and type the name into Search mods under Verified Modrinth catalog. Mods that only run on a player's computer are left out of the results, so Sodium will not turn up there.

3. 3

   Install one mod

   Click Verify & install. The panel picks the newest stable release, fetches required dependencies with it, and checks each file's SHA-512 before anything lands in mods. When a mod has several stable releases for your version, a Version list on its card lets you choose.

4. 4

   Restart and confirm

   The panel reports how many verified files it installed. Restart from the Console tab; on Fabric the start log prints Loading with the number of mods and one line per mod, so you can see the new one was picked up.

If a mod only has alpha or beta files for your version, the install stops with No exact stable fabric 26.2 build exists for followed by the mod's name, and nothing is written. Mods installed this way show up on the Updates card with an Update button once Modrinth has a newer version; files you uploaded yourself on the Files tab cannot be followed there.

Measure the difference instead of guessing

A smoother evening after an install proves little; maybe nobody was exploring. Compare two measurements from similar moments, with one change between them.

1. 1

   Install spark first, on its own

   spark has builds for Fabric, NeoForge and Forge on 26.2. Install it before any performance mod, so the first measurement shows the server as it was.

2. 2

   Record a baseline

   On a normal busy evening, run spark tps and spark health show --memory in the console, then spark profiler start --timeout 300. Keep the viewer link that spark prints when the five minutes are up.

3. 3

   Add one mod or one stack

   Install Lithium, or the whole stack you picked above, and restart. Adding mods one at a time takes longer but tells you which one earned its place.

4. 4

   Record again at a similar moment

   Similar players and activity, same commands. Compare tick durations, heap figures and the share of the main thread that entities, chunks and lighting take.

spark tps
spark health show --memory
spark profiler start --timeout 300
spark tickmonitor --threshold-tick 60
spark gc

spark tickmonitor --threshold-tick 60 reports every tick that runs past 60 milliseconds while it is on, which makes a before and after count of slow ticks easy. spark gc lists recent garbage collections and how long they paused the server, worth reading next to the memory figures when you try FerriteCore. For reading a profile in detail, the spark guide walks through the tree.

Switching off one part when something breaks

When a farm or a machine stops working after you installed a performance mod, you do not always have to remove the mod. Two of them let you turn off a single change.

mixin.ai.pathing=false

Lithium creates config/lithium.properties on its first start with only a comment in it. An empty file means every option is at its default; each line you add overrides one group of changes, like the pathfinding line above. Lithium documents its options separately for Fabric and NeoForge, so look the names up for your loader, and restart after each edit.

Moonrise keeps its settings in config/moonrise.yml, with an explanation written next to each option in the file itself. It also lowers how hard the server tries to catch up after a lag spike, so a server that briefly fell behind does not rush through ticks afterwards. If a problem remains, remove the mods one by one from Installed mods on the Mods tab, restarting in between, until the behaviour comes back.