Username ↔ UUID
The UUID is a player's real identity: their inventory, ranks and bans are tied to it, not to their username. One username has two, the official one, assigned by Mojang, and the one an online-mode=false server derives from the username.
Bulk UUID lookup
PremiumPaste up to a hundred usernames and get their official and offline UUIDs, ready to copy or download as CSV.
Why two UUIDs?
- Official: assigned to the account, it never changes, even when the player changes username. It's the one used by an online-mode=true server or one behind a properly configured proxy.
- Offline: computed from “OfflinePlayer:username”. Changing username means changing identity.
- Switching a server from one to the other makes every player “lose” their inventory and ranks: player files have to be converted using the UUIDs on this page.