Minecraft UUID and Skin Lookup

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minecraft username to uuid

Minecraft username to UUID (and UUID to username)

Type the username in the Lookup tab. The tool asks Mojang and returns the UUID in the five forms used in practice, each with its own copy button. If you paste a UUID instead of a name, it shows the current username of the account.

What Mojang returns and how each format comes from the same number

The name lookup uses the api.minecraftservices.com/minecraft/profile/lookup/name endpoint followed by the username. The reply is JSON with two fields: id, which is 32 hexadecimal digits without dashes, and name, the username with its official capitalization. The search ignores case, so notch and Notch reach the same account. If the name belongs to nobody today, Mojang answers 404. An old name that the owner has since changed also gives 404, because the API only knows the current name.
The other formats come from that same 128-bit number. With dashes, the UUID is split into groups of 8, 4, 4, 4 and 12 digits, the format used by whitelist.json and ops.json. The int array [I;a,b,c,d] splits the 128 bits into four signed 32-bit integers, most to least significant, and is the NBT form since 1.16 and the one modern commands use. The two longs are the mostSigBits and leastSigBits of java.util.UUID, the upper and lower 64 bits, also signed. The tool shows all five and accepts any of them back.
For the reverse path, from UUID to name, the tool queries the profile on Mojang's session server, which returns the current name and the textures. A UUID that does not exist returns an empty reply, and the tool says the account was not found. The UUID never changes, even when the person renames, which is why servers store the UUID and not the name. If you have a UUID saved in a plugin and need to know whose it is today, this lookup is the answer.
Mojang limits lookups to about 200 requests per 2 minutes per IP, and every visitor of the tool shares our server's IP. That is why replies are cached for a few minutes and each visitor has a limit of their own. If you get the rate limit notice, wait the indicated time. Usernames follow the rule of 3 to 16 characters among letters, numbers and underscore; the API still resolves a few old accounts with shorter names.

Checked examples

Name to UUID

Input: Notch
Expected output: 069a79f4-44e9-4726-a5be-fca90e38aaf5

Mojang reply on 2026-10-18, with dashes.

Adding the dashes

Input: 069a79f444e94726a5befca90e38aaf5
Expected output: 069a79f4-44e9-4726-a5be-fca90e38aaf5

Groups of 8-4-4-4-12.

NBT int array

Input: 069a79f4-44e9-4726-a5be-fca90e38aaf5
Expected output: [I;110787060,1156138790,-1514210135,238594805]

Four signed 32-bit integers.

The two longs

Input: 069a79f4-44e9-4726-a5be-fca90e38aaf5
Expected output: 475826800676128550 e -6503483008858150155

mostSigBits and leastSigBits of java.util.UUID.

Name too long

Input: abcdefghijklmnopq
Expected output: 17 > 16

The name has 17 characters, over the maximum of 16, and is rejected before any lookup.

Full tool FAQ

How do I find a Minecraft player's UUID from their username?

Type the username in the Lookup tab. The tool asks the Mojang API and shows the UUID with dashes (069a79f4-44e9-4726-a5be-fca90e38aaf5 for Notch), without dashes and as the NBT int array. The lookup is case-insensitive and the result carries the official capitalization. The name must exist today: old names that the player has since changed do not resolve.

Does the UUID change when someone changes their username?

What is the difference between the online UUID and the offline UUID?

How is the offline UUID computed, and does it match the Java server?

What is the [I;a,b,c,d] format and when do I use it?

How do I give a player's head with /give?

How can I tell if a skin is classic (Steve) or slim (Alex)?

Can I download the skin and cape of any player?

How many usernames can I convert at once?

Why does my username not show up, or I get a rate limit error?

Frequently asked questions

Does the username need the right capitalization?

Not for the lookup: Mojang ignores case and returns the name with its official spelling. But on offline servers the case changes the UUID, and that is where care matters.

Does it work for Bedrock Edition accounts?

The tool queries the Java profile at Mojang. A profile that exists only on Bedrock does not show up, and Bedrock uses another identifier, so in that case the answer is account not found.

Why does the UUID have no dashes in Mojang's reply?

The API returns the 32 digits run together. The dashes are presentation only. whitelist.json requires the dashed form, and the tool provides both.

Next steps

What Mojang returns and how each format comes from the same number

The name lookup uses the api.minecraftservices.com/minecraft/profile/lookup/name endpoint followed by the username. The reply is JSON with two fields: id, which is 32 hexadecimal digits without dashes, and name, the username with its official capitalization. The search ignores case, so notch and Notch reach the same account. If the name belongs to nobody today, Mojang answers 404. An old name that the owner has since changed also gives 404, because the API only knows the current name.

The other formats come from that same 128-bit number. With dashes, the UUID is split into groups of 8, 4, 4, 4 and 12 digits, the format used by whitelist.json and ops.json. The int array [I;a,b,c,d] splits the 128 bits into four signed 32-bit integers, most to least significant, and is the NBT form since 1.16 and the one modern commands use. The two longs are the mostSigBits and leastSigBits of java.util.UUID, the upper and lower 64 bits, also signed. The tool shows all five and accepts any of them back.

For the reverse path, from UUID to name, the tool queries the profile on Mojang's session server, which returns the current name and the textures. A UUID that does not exist returns an empty reply, and the tool says the account was not found. The UUID never changes, even when the person renames, which is why servers store the UUID and not the name. If you have a UUID saved in a plugin and need to know whose it is today, this lookup is the answer.

Mojang limits lookups to about 200 requests per 2 minutes per IP, and every visitor of the tool shares our server's IP. That is why replies are cached for a few minutes and each visitor has a limit of their own. If you get the rate limit notice, wait the indicated time. Usernames follow the rule of 3 to 16 characters among letters, numbers and underscore; the API still resolves a few old accounts with shorter names.

Checked examples

Name to UUID

Input: Notch
Expected output: 069a79f4-44e9-4726-a5be-fca90e38aaf5

Mojang reply on 2026-10-18, with dashes.

Adding the dashes

Input: 069a79f444e94726a5befca90e38aaf5
Expected output: 069a79f4-44e9-4726-a5be-fca90e38aaf5

Groups of 8-4-4-4-12.

NBT int array

Input: 069a79f4-44e9-4726-a5be-fca90e38aaf5
Expected output: [I;110787060,1156138790,-1514210135,238594805]

Four signed 32-bit integers.

The two longs

Input: 069a79f4-44e9-4726-a5be-fca90e38aaf5
Expected output: 475826800676128550 e -6503483008858150155

mostSigBits and leastSigBits of java.util.UUID.

Name too long

Input: abcdefghijklmnopq
Expected output: 17 > 16

The name has 17 characters, over the maximum of 16, and is rejected before any lookup.

Full tool FAQ

How do I find a Minecraft player's UUID from their username?

Does the UUID change when someone changes their username?

What is the difference between the online UUID and the offline UUID?

How is the offline UUID computed, and does it match the Java server?

What is the [I;a,b,c,d] format and when do I use it?

How do I give a player's head with /give?

How can I tell if a skin is classic (Steve) or slim (Alex)?

Can I download the skin and cape of any player?

How many usernames can I convert at once?

Why does my username not show up, or I get a rate limit error?

Frequently asked questions

Does the username need the right capitalization?

Not for the lookup: Mojang ignores case and returns the name with its official spelling. But on offline servers the case changes the UUID, and that is where care matters.

Does it work for Bedrock Edition accounts?

The tool queries the Java profile at Mojang. A profile that exists only on Bedrock does not show up, and Bedrock uses another identifier, so in that case the answer is account not found.

Why does the UUID have no dashes in Mojang's reply?

The API returns the 32 digits run together. The dashes are presentation only. whitelist.json requires the dashed form, and the tool provides both.