CleanJoin
by epicskydex
CleanJoin, a NeoForge performance mod, spreads the work of a player joining a busy server over several ticks, so login waves cause less lag.
What it does
When a player joins, CleanJoin reads the nearby chunks on a separate track, so the main thread keeps running while the disk is read.
Passive mobs far from every player have their behavior logic paused and run on a worker thread, which lowers the pathfinding load during peak hours. Game state is written back through a route that runs safely on the main thread, which keeps the work clear of the Bukkit event system on hybrid servers.
The mod is built for high-population NeoForge servers, including Arclight hybrid environments where NeoForge mods and Bukkit plugins run at the same time. It is server-side only, so players join without installing anything. It is published for NeoForge and is not open source; the license is All rights reserved.
Key features
Asynchronous chunk preloading
Chunks near a joining player are loaded in the background, so the main thread does not stall while the disk is read.
Spread entity sync
Initial entity packets are sent across several ticks instead of all on the first tick after a join.
Login-wave hostile mob priority
For two seconds after a join, hostile mobs are held back so arriving players are the first to be served.
Distant mob AI throttling
Passive mobs far from every player have their AI suspended on a worker thread, reducing pathfinding load.
Compatibility
Latest build for each game version and loader.
1.21.x11 of 11 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Who it’s for: Server owners running NeoForge, especially high-population servers and Arclight hybrid environments where login load is a concern.
How it compares
Astruct is a NeoForge server-side mod for 1.21.1, under the MIT License, and is open source. Arcadia Patch Create is also NeoForge and server-side only, under the MIT License and open source, with files for 1.21.1 – 26.2. Shinoyuki-BetterAutoSave covers Forge and NeoForge for 1.20.1 – 1.21.1 and is open source under the GNU Affero General Public License v3.0 or later, while CleanJoin is not open source.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| CleanJoin | NeoForge | 1.21.1 – 1.21.11 | Server-side only | 2026-07-22 |
| Astruct | NeoForge | 1.21.1 | Server-side only | 2026-01-11 |
| Arcadia Patch Create | NeoForge | 1.21.1 – 26.2 | Server-side only | 2026-09-05 |
| Shinoyuki-BetterAutoSave | Forge and NeoForge | 1.20.1 – 1.21.1 | Server-side only | 2026-09-21 |
Questions
Does CleanJoin need to be installed on clients?
Which loader and versions does CleanJoin support?
Does CleanJoin work alongside Bukkit plugins?
In the catalog
CleanJoin is one of 3,545 Optimization mods on ModsFinder, and one of 1,250 Optimization mods for NeoForge. 19,862 mods support Minecraft 1.21.11.
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What the author says
CleanJoin is a server-side performance mod designed for high-population NeoForge servers and Arclight hybrid environments. When many players join at the same time, the server main thread gets hammered with chunk loading, entity tracking and packet serialization all at once, causing TPS drops and watchdog crashes…
Official listing
- Modrinth page
- modrinth.com/mod/clean-join
- Owner
- epicskydex
- Published
- 2026-07-22
- Updated on Modrinth
- 2026-07-22
- Facts verified
- 2026-10-15