BadOptimizations

Optimization mod that focuses on things other than rendering

by
39.4M Downloads
fabricforgeneoforgeoptimization
Configure a Compatible Minecraft Server

About this Mod

BadOptimizations

A collection of mostly micro optimizations that add up to something bigger!

What does it do?

Multiple things:

  • 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?

Depends on your system and luck, but on my own PC, an RTX 3060, intel i7 12700 and 4GB of allocated ram on Fabulously Optimized:


Without toasts, it goes from 1926-1955 FPS:



To 2008-2023 FPS:



And with toasts, it goes from 1351-1384 FPS:



To 1414-1458 FPS:


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.)

Available Versions

2.4.1 (26.2/fabric)release
MC 26.2fabric
June 16, 2026
2.4.1 (26.2/neoforge)release
MC 26.2neoforge
June 16, 2026
2.4.1 (26.1-26.1.2/fabric)release
MC 26.1, 26.1.1, 26.1.2fabric
March 29, 2026
2.4.1 (26.1-26.1.2/neoforge)release
MC 26.1, 26.1.1, 26.1.2neoforge
March 29, 2026
2.4.1 (1.21.11)release
MC 1.21.11fabric, neoforge
December 16, 2025

How to Install BadOptimizations on Your Client

1

Install the Mod Loader Locally

Install fabric for your local Minecraft version.

2

Download the Matching File

Choose the BadOptimizations file for fabric and Minecraft 26.2.

3

Install Mod

Place the .jar file in your local .minecraft/mods folder and restart Minecraft. No server-side installation is required.

Compatibility

Mod Loaders

fabricforgeneoforge

Minecraft Versions

26.2, 26.1.2, 26.1.1 (+23 more)

Server-side

Unsupported

Recommended RAM

4 GB(min. 3 GB)

Frequently Asked Questions

Does BadOptimizations need to be installed on the Minecraft server?

No. Modrinth marks BadOptimizations as unsupported on the server side. Install it only in your local Minecraft mods folder. Your server can remain unchanged unless the mod page lists an additional dependency.

Which version and loader does BadOptimizations require?

Use a file for fabric, forge, neoforge and your exact Minecraft version. Supported versions include 26.2, 26.1.2, 26.1.1. Files for different loaders are not interchangeable.

BadOptimizations is not working – what should I check?

First check the Minecraft version, loader version and required dependencies. Put the .jar file in your local .minecraft/mods folder and remove older duplicates. Because this mod is client-side, adding server RAM will not fix it.

Minecraft Server for Your Group

BadOptimizations stays on your client. Host a compatible world for your group.

Recommended RAM
4 GBfrom €5.2/mo
Minimum 3 GB | per 8 players
Create Server Now
Client Compatibility Guide
NVMe SSD Storage
DDoS Protection included

Details

License
MIT License
Server-side
Unsupported

Supported Versions

26.226.1.226.1.126.11.21.111.21.101.21.91.21.81.21.71.21.6+16 more