Starlight (Fabric)
by spottedleaf
Starlight replaces the light engine of Fabric builds to cut the cost of light updates on busy servers and in heavy builds, and it also fixes lighting errors.
What it does
Starlight rewrites the light engine that Minecraft uses to compute block and sky light. The rewrite targets two kinds of slowdown: chunk generation, and light updates caused by block editing at high y-levels or by ordinary block changes. The mod was first written for large dedicated servers, where the original engine was slow enough to cause lag, and it was later ported to Fabric so it could be offered to players on the client side as well.
Because the rewrite reaches deep into how lighting works, the mod is invasive. A server running Starlight accepts clients that run other lighting-compatible setups, and a client running Starlight can connect to servers that do not have it. The project's technical notes describe how the performance gains are achieved, and the published graphs compare chunk generation and block editing for earlier releases. For the newest release, the maintainer removed the chunk generation benchmark because the difference was too small to show.
Key features
Rewritten light engine
The light engine is replaced entirely, which targets both the speed of light calculation and the errors in the original code.
Faster block editing
Light updates from block edits at high y-levels are handled with less work than in the original engine, according to the published graphs.
Chunk generation speedup
Chunk generation is one of the two areas the rewrite targets, with graphs published for earlier releases.
Technical documentation
The project publishes a technical details document that explains how the rewrite achieves its performance.
Compatibility
Latest build for each game version and loader.
1.20.x5 of 5 versions with builds
1.19.x5 of 5 versions with builds
1.18.x3 of 3 versions with builds
1.17.x2 of 2 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Large dedicated servers
Servers with many players or heavy building were the original target, where slow light updates caused the most trouble.
Client-side use
Players can install the mod on their own client to get the same lighting changes without requiring the server to run it.
Who it’s for: Players and server owners who run Fabric and want faster or more accurate lighting. Since the rewrite is invasive, it suits people who accept a change to a core game system.
How it compares
Phosphor is a Fabric mod for 1.16.2 – 1.19.4 that is open source under the GNU Lesser General Public License v3.0 only, and it works on either side, so neither needs it. ScalableLux is published for Fabric and NeoForge across 1.21 – 26.3 under the same license, and it also works on either side. BeeFix is server-side only, runs on Fabric and Quilt for 1.18.2 – 1.19 and is licensed under the MIT License, so it differs from Starlight in environment and license.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Starlight (Fabric) | Fabric | 1.17 – 1.20.4 | Client or server, optional | 2023-12-10 |
| Phosphor | Fabric | 1.16.2 – 1.19.4 | Client or server, optional | 2022-06-14 |
| ScalableLux | Fabric and NeoForge | 1.21 – 26.3 | Client or server, optional | 2026-09-16 |
| BeeFix | Fabric and Quilt | 1.18.2 – 1.19 | Server-side only | 2022-09-22 |
Questions
Does Starlight need to be installed on both the client and the server?
Which Minecraft versions does the Fabric build support?
Why was the chunk generation benchmark removed for the newest release?
In the catalog
Starlight (Fabric) is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 13,907 mods support Minecraft 1.20.4.
More from spottedleaf
Similar mods
What the author says
Starlight ================== Fabric mod for rewriting the light engine to fix lighting performance and lighting errors. Compatibility ------------------ Starlight can be installed either on the dedicated server or client. It is not required to be installed on both sides. If you have Starlight on the server, clients…
Official listing
- Modrinth page
- modrinth.com/mod/starlight
- Owner
- spottedleaf
- Published
- 2021-08-29
- Updated on Modrinth
- 2023-12-10
- Facts verified
- 2026-10-15