Minecraft Bedrock UUID Generator (RFC 4122 v4)
Generate cryptographically compliant RFC 4122 version 4 UUID pairs formatted specifically for Minecraft Bedrock Behavior Packs, Resource Packs, and manifest.json headers and modules.
header.uuid and as dependency target for companion packsmodules[0].uuid to identify the data or resources moduleRFC 4122 v4 Entropy Math & Collision Probability
0100 = 4), and 2 bits are reserved for the variant (10 = RFC 4122).
This leaves exactly 122 bits of cryptographically random entropy.
5 Critical Bedrock Add-On UUID Traps
1. Identical Header & Module UUID Collision
A pack's header.uuid and modules[0].uuid MUST be completely different. Copying the header UUID into the module block causes Minecraft Bedrock to reject the manifest as duplicate or invalid, preventing the pack from loading in world settings.
2. Reusing UUIDs Across Different Add-On Projects
Minecraft Bedrock tracks installed add-ons by their UUID in the internal LevelDB database, not by directory name. If you copy-paste a manifest template into a new project without generating fresh UUIDs, the game will overwrite your original pack or fail with silent import errors.
3. Forgetting Dependency Header UUID Binding
When linking a Behavior Pack to its companion Resource Pack in dependencies, you must specify the Resource Pack's Header UUID, NOT its module UUID. Binding the module UUID breaks automatic pack association on multiplayer worlds.
4. Omitting Semantic Version Bumps on Modified Packs
When publishing updates to an existing pack, you keep the same UUIDs but MUST increment the version array (e.g. [1, 0, 0] to [1, 0, 1]). Without a version bump, players on dedicated servers will execute stale cached scripts and textures.
5. Case Sensitivity & Formatting Non-Compliance
Minecraft Bedrock JSON schemas require standard lowercase, hyphen-separated 8-4-4-4-12 hex format. Adding curly braces {...}, omitting hyphens, or using uppercase characters can cause validation failures on consoles and mobile devices.