What BadOptimizations works with.
| Platform | Java Edition |
|---|---|
| Loaders | Fabric, Forge, NeoForge |
| Minecraft versions | 1.19.1, 1.20.1, 1.20.4, 1.20.6, 1.21.1, 1.21.5, 1.21.8, 1.21.11, 26.1, 26.2 |
| Environment | Client |
BadOptimizations is a Minecraft Java mod for Fabric, Forge, and NeoForge that trims client-side overhead outside of rendering. It caches lightmap updates, simplifies sky color calculations, and skips idle debug-renderer logic that normally runs every tick even when nothing needs it. The mod is client-only, has no required dependencies, and every optimization can be turned off in its config file.
What BadOptimizations changes
Minecraft recalculates lightmap textures and sky color every tick by default, even when nothing that affects them has changed. BadOptimizations caches both and only redoes the work when a real change happens, such as a potion effect, a gamma slider adjustment, or crossing into a biome with a different sky color. It also gates Minecraft's four debug renderers (bees, game events, game test, and villager AI) so their logic only runs when debug mode is active and a server is actually sending data to process.
Loader and Minecraft version support
- Fabric and NeoForge builds are current through Minecraft 26.2.
- The Forge build is capped at Minecraft 1.20.1, last published in December 2025.
- Client required, server unsupported. Modrinth lists no server-side role for this mod.
- No required dependencies, including Fabric API.
- License: MIT.
Installing BadOptimizations
- 1.Install the matching mod loader (Fabric, Forge, or NeoForge) for your Minecraft version.
- 2.Download the BadOptimizations jar file for that loader and version from Modrinth.
- 3.Place the jar in your Minecraft mods folder and launch the matching loader profile.
- 4.Open the generated config file to disable any individual optimization that conflicts with another mod.
Configuration and compatibility with other optimization mods
Every optimization in BadOptimizations can be switched off independently in its config file, which helps when another mod already patches the same lightmap or sky color code. The mod also lets other developers register their mod as incompatible with a specific option, so BadOptimizations disables just that option automatically instead of conflicting outright.
BadOptimizations does not overlap with rendering-focused mods like Sodium, or with game-logic mods like Lithium, which optimizes physics, mob AI, and block ticking instead. Players who already run FerriteCore for memory or ModernFix for load times commonly add BadOptimizations alongside them, since each targets a separate part of the client rather than competing for the same fix.
BadOptimizations covered in an optimization mod pack build
Questions about BadOptimizations.
5 questions
How do I install BadOptimizations?
Install the matching mod loader (Fabric, Forge, or NeoForge) for your Minecraft version, then download the BadOptimizations jar for that same loader and version from Modrinth. Drop the jar in your mods folder and launch the loader profile. No extra dependency is required to run it.
Does BadOptimizations work with Forge?
Yes, but the Forge build lags behind. Fabric and NeoForge currently reach Minecraft 26.2, while the Forge build tops out at 1.20.1, last published in December 2025. Forge players should check Modrinth's version list before assuming parity with the other two loaders.
Is BadOptimizations compatible with Lithium?
Yes. Lithium optimizes game logic such as physics, mob AI, and block ticking, while BadOptimizations caches lightmap updates, sky color calculations, and idle debug-renderer work. The two touch different systems, so they are commonly run together rather than as alternatives to each other.
Does BadOptimizations work on multiplayer servers?
No. Modrinth lists BadOptimizations as required on the client and unsupported on the server, since its optimizations target client-side logic rather than server tick processing. Installing it on players' clients is the supported setup, and a dedicated server does not need the jar.
Which Minecraft version does BadOptimizations support?
It depends on the loader. Fabric and NeoForge builds are current on Minecraft 26.2, while the Forge build is capped at 1.20.1. Check the version list on Modrinth for the exact file that matches your loader and Minecraft version before downloading.
