Phosphor
by CaffeineMC
With Phosphor installed, the lighting engine of Minecraft 1.16.2 – 1.19.4 runs through rewritten code that cuts chunk generation time on Fabric.
What it does
The mod rewrites part of the lighting engine, the area the author describes as among the game's least efficient. Chunks take less time to generate, and the stutters that appear as chunks load on the client are reduced. Phosphor changes no features or behaviors of vanilla, which is why the mod has been officially allowed in Minecraft speedrunning.
Phosphor works on the client and on the server, and it can be installed on a server without requiring clients to also have it. Only Fabric Loader is needed; neither Fabric API nor any other mod is required. Existing worlds keep working, so no new world has to be created. Files cover 1.16.2 – 1.19.4 across 14 release versions, and the source code is open source under the GNU Lesser General Public License v3.0 only.
Key features
Faster chunk generation
The lighting engine code is optimized so that new chunks take less time to generate during play.
Fewer loading stutters
Frame drops caused by loading chunks on the client are reduced, particularly in large areas.
Unchanged vanilla behavior
Game features and behaviors stay as in vanilla, with no added items, blocks or gameplay rules.
Single-player and servers
The same optimizations apply in single-player worlds and on large multiplayer servers.
Compatibility
Latest build for each game version and loader.
1.19.x5 of 5 versions with builds
1.18.x3 of 3 versions with builds
1.17.x2 of 2 versions with builds
1.16.x4 of 4 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Large multiplayer servers
A server owner can add the mod on the server alone, and players join without installing anything.
Single-player exploration
Players who travel quickly through new terrain see less stutter while chunks load around them.
Who it’s for: Players and server owners who want faster chunk loading on Fabric without changing how the game plays. Phosphor is no longer maintained, and its author notes that most of its patches no longer apply to newer releases, so it suits the versions it covers, up to 1.19.4.
How it compares
Starlight is open source under the GNU Lesser General Public License v3.0 only, for Fabric, with files for 1.17 – 1.20.4 and the same client or server environment as Phosphor. ScalableLux Backport is also open source under that license, but it targets only 1.16.5, so it covers a much narrower range of versions.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Phosphor | Fabric | 1.16.2 – 1.19.4 | Client or server, optional | 2022-06-14 |
| Starlight (Fabric) | Fabric | 1.17 – 1.20.4 | Client or server, optional | 2023-12-10 |
| ScalableLux Backport | Fabric | 1.16.5 | Client or server, optional | 2026-06-03 |
Questions
Does Phosphor need Fabric API?
Do clients need Phosphor to join a server that runs it?
Will existing worlds work after adding Phosphor?
Is Phosphor still updated for newer versions?
In the catalog
Phosphor is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 9,374 mods support Minecraft 1.19.4.
More from CaffeineMC
Similar mods
What the author says
Phosphor is not currently maintained due to a lack of available time and resources. As of Minecraft 1.20, there have been significant improvements to the game's lighting engine, and most of Phosphor's patches are no longer applicable or useful. (see more)) You may also be interested in our other mods, Sodium and…
Official listing
- Modrinth page
- modrinth.com/mod/phosphor
- Owner
- CaffeineMC
- Published
- 2021-01-03
- Updated on Modrinth
- 2022-06-14
- Facts verified
- 2026-10-15