Minecraft pack checker
A pack that imports can still do nothing. Start by checking its metadata: Java pack.mcmeta or Bedrock manifest.json. Find concrete JSON and declaration problems, then test the full pack in a copied world.
Free to use. No account, API key or upload required.
Check your pack metadata
File contents stay in your browser. This checker does not upload, execute or save them.
Strict JSON only, up to 128 KiB. Choose the pack type: Java data and resource format numbers differ.
Find the problem before importing
Check JSON syntax, declared Java format ranges, or Bedrock header fields, module UUIDs and dependency declarations.
- Extract pack.mcmeta or manifest.json.
- Choose its pack type and open or paste it.
- Check metadata, then test the full pack in Minecraft.
A successful import is only one step. A correctly structured manifest cannot prove that a script runs or that every device supports the pack.
What this metadata check covers
| File | Checks | Still needs testing |
|---|---|---|
| pack.mcmeta | Strict JSON, pack object, description, legacy format number, modern range shape and order. | Target Minecraft release, zip root, commands, data paths and resource files. |
| manifest.json | Format 1/2 header fields, version shapes, distinct UUIDs, module declarations and dependency identity/version syntax. | Companion packs, script entry files, API availability, textures, activation and device support. |
The checker inspects one metadata file up to 128 KiB. It does not open zip, mcpack or mcaddon archives. Extract the metadata first. Manifest format 3 and unknown module types are marked for manual review. A clean result describes only the supported checks; it does not certify the whole pack, its safety or gameplay.
Three metadata problems explained
Modern Java metadata with only pack_format
{ "pack": { "description": "My datapack", "pack_format": 88 } }For this Java datapack format, add min_format and max_format. Minecraft 1.21.9 introduced explicit minimum and maximum format versions. pack_format can be omitted for a modern-only range; older compatibility declarations have different requirements.
The minimum is greater than the maximum
{ "pack": { "description": "My datapack", "min_format": [88, 2], "max_format": [88, 1] } }The lower bound cannot exceed the upper bound. A scalar max_format such as 88 includes every minor version of that major format; [88, 1] instead ends at minor version 1. Changing a number does not convert the pack's actual commands or data.
A Bedrock module reuses the header UUID
"header": { "uuid": "…" },
"modules": [{ "uuid": "the same UUID" }]The header and each module need their own UUID. A dependency that points to a companion pack uses that companion's header UUID. Compare the actual files before changing identifiers: an existing dependency may need the corresponding update.
Metadata is one part of a working installation
- Confirm the edition and actual file type. Java datapacks and resource packs use pack.mcmeta. Bedrock packs use a manifest. A Fabric source project has a separate build and loader workflow; this tool does not validate it.
- Inspect the archive layout. Java pack.mcmeta belongs at the pack root, beside data/ for a datapack or assets/ for a resource pack. A second enclosing folder is a common discovery problem. Bedrock companion packs each need their own manifest.
- Match the intended game version. A format declaration is a compatibility claim, not an automatic converter. Newer command or asset syntax may require actual file changes. Read Mojang's release notes or Microsoft's manifest reference for that version.
- Activate and exercise the pack. Back up the world. In Java, inspect reload errors and the enabled datapack list. In Bedrock, activate required behavior and resource packs and test the documented trigger. Local import workflows differ on consoles.
Before you change your pack
Does changing pack_format update my datapack?
No. It changes what the metadata declares. Commands, directory names, components and other data may also need migration. Test the intended behavior after any version change.
Why does my Bedrock add-on import but not work?
Import, activation and execution are separate steps. Confirm world activation, companion resources, minimum engine version and the exact script dependencies. This checker can inspect declarations but cannot load your scripts or verify device behavior.
Can I check packs created somewhere else?
Yes. Paste or select the metadata from your own pack or one you are allowed to inspect. No Mine Mod AI account or generated output is required. Nothing in this check grants permission to redistribute someone else's files.
Will it repair or upload my files?
No. It reads strict JSON locally and explains findings. You make any edits in your own copy. It neither rewrites the metadata nor uploads its contents.
Start a supported pack from an example
Mine Mod AI generates supported Java datapacks and Bedrock add-ons. Inspect an example's output and installation requirements before building your own version.
Reference and maintenance
Maintained by Mine Mod AI. This tool applies a bounded set of documented metadata checks, rather than running Minecraft. Documentation reviewed on October 28, 2026. Follow the current official reference when a preview format or game release differs.