MCUtility

How to find a Minecraft player’s UUID

Enter the player’s Java Edition username in the UUID Lookup. It asks Mojang for the account and shows the UUID in both forms that servers and tools use.

Java Edition · Published

Steps

  1. Open the UUID Lookup and type the username. Capitalisation doesn’t matter: notch finds the same account as Notch.
  2. Copy the dashed UUID for commands, whitelist.json, ops.json and most plugins.
  3. Copy the undashed UUID when a web service or API asks for it without dashes.
  4. If the server runs with online-mode=false, use the offline-mode UUID shown underneath instead. The section below explains why.

The lookup also works the other way round: paste a UUID to get the account’s current name.

Dashed and undashed are the same UUID

A UUID is 32 hexadecimal digits. The dashed form only adds hyphens after the 8th, 12th, 16th and 20th digit, so both lines below identify Notch’s account:

069a79f4-44e9-4726-a5be-fca90e38aaf5
069a79f444e94726a5befca90e38aaf5

If a plugin or file rejects one form, try the other. Nothing else changes between them.

Finding a UUID inside the game

An operator can run /data get entity <player> UUID while the player is online. The game answers with an array of four numbers such as [I; 110787060, 1156138790, -1514210135, 238594805]. That is the same UUID in the format Java Edition uses for entity data since 1.16. The Minecraft UUID format reference shows how the forms convert.

A server also records names and UUIDs of players who have joined in usercache.json, next to server.properties.

Offline-mode UUIDs

A server with online-mode=false doesn’t check players against Mojang, so it can’t know their real UUID. It calculates one from the name instead, by hashing the text OfflinePlayer: followed by the exact name. For Notch that gives b50ad385-829d-3141-a216-7e7d7539ba7f.

  • The offline UUID never matches the account UUID, so data saved on an online-mode server doesn’t carry over.
  • Capitalisation matters: notch and Notch get different offline UUIDs.
  • Anyone can join with any name when online mode is off, so the name is the only thing tying a player to their data.

What a UUID lookup can’t tell you

  • Bedrock Edition players: Bedrock accounts are identified by an Xbox user ID (XUID), not a Mojang UUID.
  • Previous names: Mojang removed public access to name history in 2022.
  • Online status or bans: the profile service only knows the account’s name, UUID and skin.