Minecraft Offline UUID Generator
Generate offline-mode (cracked) UUIDs from usernames with the exact OfflinePlayer:<name> algorithm Spigot/Paper use. Paste a list, export as JSON, CSV or XML.
| Name | Offline UUID |
|---|---|
| Notch | |
| jeb_ | |
| Steve |
How offline UUIDs are calculated
When online-mode=false, the server can't ask Mojang who a player is, so it derives a UUID from the name: UUID.nameUUIDFromBytes(("OfflinePlayer:" + name).getBytes(UTF_8)). That's an MD5 hash with the version set to 3 and the IETF variant bits set, fully deterministic, so every offline server computes the same UUID for the same name.
FAQ
What is an offline (cracked) UUID?
On an offline-mode server (online-mode=false), there is no Mojang authentication, so the server makes a UUID from the username itself: UUID.nameUUIDFromBytes("OfflinePlayer:<name>"), a type-3 MD5 UUID. The same name always gives the same offline UUID.
How is it different from a real (online) UUID?
A real UUID is issued by Mojang and tied to the account permanently, regardless of name. An offline UUID is derived purely from the current username: change the name and the UUID changes, and two servers will agree only because they run the same formula.
When do I need offline UUIDs?
For cracked/offline servers, for local testing, when pre-seeding whitelist.json/ops.json on an offline server, or when migrating world data between online and offline mode (player data is stored under the UUID).
Is this generator accurate?
Yes. It uses the exact Java algorithm (MD5 of "OfflinePlayer:<name>" with the version/variant bits set), the same one Spigot/Paper use in offline mode.
Can I generate many at once?
Yes. Paste one username per line (up to 1000) and export the results as JSON, CSV or XML in dashed or undashed format.
Should I run my server in offline mode?
Generally no. Offline mode lets anyone join under any name (including impersonating ops), so it is a security risk for public servers. Use it only for testing or behind a proxy that authenticates players.