Minecraft Offline UUID Generator
Generate offline-mode (cracked) UUIDs from usernames — 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.