ModsFinder

Legacy OptiFabric

by tildejustin

Legacy OptiFabric lets OptiFine be loaded as a Legacy Fabric or Ornithe mod on older Minecraft Java Edition versions, without a separate OptiFine installer.

Legacy FabricOrnitheClient-side onlyMozilla Public License 2.0Open sourceb1.7 – 1.14.4

What it does

OptiFine is distributed as an installer rather than a mod, and the mod reads the installer jar, extracts its classes in a throwaway classloader, and replaces the matching Minecraft classes with OptiFine's versions. Rename mappings are applied with the original Minecraft jar, so the replacement classes line up with the game. The mod is built for Legacy Fabric and Ornithe, and its files target game versions b1.7 – 1.14.4.

The mod is client-side only, so servers do not need it. Latest files are 2.3.6+1.3.1-1.13.2 for 1.13.2 on Legacy Fabric and 2.3.6+b1.7.3-1.14.4 for 1.14.4 on Ornithe, both dated 2025-08-31. Snapshot builds are published as well. Legacy OptiFabric is open source under the Mozilla Public License 2.0, and its source code and issue tracker are public. It is maintained by tildejustin and was first published on 2023-10-23.

Key features

  1. Installer-based OptiFine loading

    The mod finds the OptiFine installer jar in the mods folder and extracts it at launch, so the user does not run a separate installer.

  2. Class replacement and remapping

    OptiFine classes replace the ones Minecraft provides, with method names translated through intermediary mappings taken from the original game jar.

  3. Bundled ASM dependency

    A fork of fabric-asm is included so the mod can apply the more extreme bytecode changes that OptiFine needs, along with the Apache Commons libraries older versions lack.

  4. Removable class list

    A file named optifabric-excluded-classes.json in the config folder lists classes to leave out of the remapped jar, such as the profiler, for users who need to revert a removal.

Compatibility

Latest build for each game version and loader.

1.14.x5 of 5 versions with builds
1.14.4Not available2.3.6+b1.7.3-1.14.4
1.14.3Not available2.3.6+b1.7.3-1.14.4
1.14.2Not available2.3.6+b1.7.3-1.14.4
1.14.1Not available2.3.6+b1.7.3-1.14.4
1.14Not available2.3.6+b1.7.3-1.14.4
1.13.x3 of 3 versions with builds
1.13.22.3.6+1.3.1-1.13.22.3.6+b1.7.3-1.14.4
1.13.1Not available2.3.6+b1.7.3-1.14.4
1.13Not available2.3.6+b1.7.3-1.14.4
1.12.x3 of 3 versions with builds
1.12.22.3.6+1.3.1-1.13.22.3.6+b1.7.3-1.14.4
1.12.1Not available2.3.6+b1.7.3-1.14.4
1.12Not available2.3.6+b1.7.3-1.14.4
1.11.x3 of 3 versions with builds
1.11.22.3.6+1.3.1-1.13.22.3.6+b1.7.3-1.14.4
1.11.1Not available2.3.6+b1.7.3-1.14.4
1.11Not available2.3.6+b1.7.3-1.14.4
1.10.x3 of 3 versions with builds
1.9.x5 of 5 versions with builds
1.8.x10 of 10 versions with builds
1.7.x9 of 9 versions with builds
1.6.x3 of 3 versions with builds
1.5.x2 of 2 versions with builds
1.4.x2 of 2 versions with builds
ReleaseBetaAlphaNot available

This mod also publishes snapshot builds. Snapshots are not shown in the matrix.

12 older game versions (1.0 – 1.4.5) not shown. All files on Modrinth

Requirements

Dependencies declared by the latest file for each loader.

Embedded 1

?
Name not publishedSummary not published
Embedded

Required by 1 mod

OfftiFine1.8.9

Questions

Does OptiFine need to be installed as a separate mod?

No. Legacy OptiFabric reads the OptiFine installer jar from the mods folder and loads its classes at launch, so the installer does not need to be run.

Does Legacy OptiFabric have to be installed on servers?

No. It is installed on the player's side alone, so servers need nothing.

What should be done if OptiFine changes stop working after an update?

Deleting the .optifine folder in the .minecraft directory forces the mod to rebuild its cache on the next launch.

In the catalog

Legacy OptiFabric is one of 3,545 Optimization mods on ModsFinder. 1,621 mods support Minecraft 1.14.4.

Optimization mods3,545Mods for 1.14.41,621

More from tildejustin

All projects
Minecart Turning1.20 – 1.21.1Half-Heart Hardcore1.0 – 1.21.4Custom Map Resetter1.3.1 – 1.21.4Gamma 51.8 – 1.12.2legacy chunk borders1.8.2 – 1.8.9NNBSP Fix1.1 – 1.19.4

Similar mods

Alternate Currenta1.0.11 – 26.3Ksyxis1.8 – 26.3Async Logger1.0 – 26.3CrashPatch (Crash Preventer)1.8.9 – 26.3McMouser1.7.10 – 26.2Custom Block Highlight (Outline / Overlay)1.8.9 – 26.3

What the author says

If you're looking for OptiFabric for 1.14 to 1.15.2 for regular Fabric instead of Ornithe, check out OptiFabric Origins OptiFabric for Legacy Fabric (1.3.1-1.13.2) and Ornithe (b1.7.3-1.14.4)
tildejustin, on the Modrinth page

Official listing

Owner
tildejustin
Published
2023-10-23
Updated on Modrinth
2025-08-31
Facts verified
2026-10-15

Tags

Optimization
Open on ModrinthCompare