Combine Resource Packs Correctly

How merging actually works

Every file in a pack has a path, like assets/minecraft/textures/block/stone.png. When two packs contain the same path, only one file can win.

Rule of thumb: images and sounds pick a winner; JSON files get merged.

Step by step

1. Back up all the packs, and write down the order of importance (the pack whose textures should win goes last).
2. Make a new folder, e.g. ServerPack/.
3. Copy the least important pack in first, then each next pack on top. When your file manager asks about replacing, note every JSON file it wants to replace; those need merging. Let images and sounds be replaced.
4. For each clashing JSON file, open both versions and combine them:

   • Item models (1.21.3 and older): combine the overrides arrays and keep them sorted by custom_model_data, lowest first. Two packs using the same number for different items is a real conflict: change one pack's numbers (and the items that use them).

     {
       "parent": "minecraft:item/handheld",
       "textures": { "layer0": "minecraft:item/diamond_sword" },
       "overrides": [
         { "predicate": { "custom_model_data": 1001 }, "model": "packa:item/ruby_sword" },
         { "predicate": { "custom_model_data": 2001 }, "model": "packb:item/frost_blade" }
       ]
     }
     

   • Item definitions (1.21.4+): custom models live in assets/<namespace>/items/<item>.json with a range_dispatch or select on custom model data. Merge the entries/cases lists the same way.

   • sounds.json / lang files: they're objects of named entries. Copy every entry from both into one object; if both define the same key, keep one.

   • Atlases: combine the sources lists.

   • Fonts: combine the providers lists.

5. Write one pack.mcmeta with the pack_format for your server version.
6. Zip the contents of ServerPack/ (so pack.mcmeta is at the top of the zip).
7. Validate the JSON: a single missing comma breaks the whole file. Paste each edited file into a JSON validator, or open the pack in a game client and check logs/latest.log for Couldn't parse errors.
8. Test in your own game, then host it.

Avoid clashes in the first place

• Use your own namespace. Put custom models and textures under assets/yourpack/... instead of assets/minecraft/.... Only the small "hook" files (the vanilla item model or item definition that points to your model) need to live in minecraft.
• Reserve number ranges for custom model data: e.g. pack A uses 1000–1999, pack B 2000–2999.
• Keep a source folder for each pack and rebuild the merged zip from them, instead of editing the merged copy by hand each time.

Let a plugin do the merging

If you run ItemsAdder, Nexo or Oraxen, they build the server pack themselves and can import other packs into it: drop the other pack into the plugin's merge/import folder (see that plugin's documentation) and reload. They handle the model and font merging for you, and many custom-item plugins conflict with a hand-set resource-pack anyway.

Optimise the result

Large merged packs download slowly. PackSquash compresses PNGs, OGGs and JSON losslessly and can cut a pack's size by half or more. Run it on the final merged pack, then recalculate the SHA-1.

Troubleshooting