BadOptimizations
Optimization mod that focuses on things other than rendering
- Loaders
- FabricNeoForgeForge
- Downloads on Modrinth
- 47.7M
- Followers on Modrinth
- 3.5K
- versions
- 139
- Updated
- September 16, 2026Sep 16
- Published
- in 2023
At a glance
Install in the game only; not needed on the server
BadOptimizations
A collection of mostly micro optimizations that add up to something bigger!
What does it do?
- Avoid updating lightmap
Updating lightmap textures are one of the most expensive parts of the client tick. During each tick, the client will do vector math to calculate lightmaps for blocks and the sky, then upload that new texture to the GPU. However, this can be completely avoided and cached if nothing affecting block brightness has changed. This mod will cancel lightmap updates if nothing that changes block brightness (e.g. gamma slider, potion effects, dimension) has changed.
- Don't do debug logic if we don't need to
Minecraft has four debug renderers that can be activated with a debug server: bees, game events, game test and villager AI. Even if there's nothing to process, the logic for these debug renderers are still executed. This mod will only execute them if debug is enabled and there is data from the server to process.
- Sky color calculation optimizations (1.21.10 and below)
Minecraft uses a cubic color sampler every frame to calculate the current sky color. This function loops 216 times to factor in surrounding biomes, even if all surrounding biomes are identical or have identical sky colors. This mod makes the color sampler only used if you are between biomes with different sky colors, and caches it for each tick. Otherwise, a shorter, simpler and faster sky color calculation is used.
That's a few of them, at least. You can disable any optimization in the config file if you need to.
How much does it help?




My mod is incompatible!
You can mark your mod as incompatible with specific BadOptimizations options. If your mod is present, BadOptimizations will automatically disable the specific options you specify.
You can also add hooks that tell BadOptimizations when the lightmap or sky color needs to be updated instead of adding a hard incompatibility to the caching optimizations.
Dependencies?
None.
(Also available on CurseForge, if that's your thing.)
FAQ
How to install BadOptimizations?
Install Fabric for your Minecraft version, download BadOptimizations for the same version and loader, put the file into the mods folder and launch the game with the loader profile.
Which Minecraft versions does BadOptimizations support?
BadOptimizations has builds for Minecraft 1.19.1–1.19.4, 1.20.1–26.3.
Is BadOptimizations needed on the server?
Client only — no need to install it on the server