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🆔 UUID / ULID Generator

Generate cryptographically random UUIDs (v4) and ULIDs in bulk. All generated in your browser using the Web Crypto API — nothing is sent to a server.

Type

Count

Format

Generated IDs

UUID v4

128-bit random identifier. The most widely used format — supported by every database, framework, and programming language.

550e8400-e29b-41d4-a716-446655440000

Format: 8-4-4-4-12 hex characters

ULID

Universally Unique Lexicographically Sortable Identifier. 128-bit with a 48-bit timestamp prefix — sorts chronologically.

01ARZ3NDEKTSV4RRFFQ69G5FAV

26 characters, Crockford Base32

How to use this tool

1 Click Generate to create one or more UUIDs.

2 Select version 4 for random UUIDs or version 1 for time-based UUIDs.

3 Choose how many to generate at once if you need a batch.

4 Copy the UUIDs for use as database primary keys, session identifiers, or request IDs.

Frequently asked questions

What is a UUID?

A Universally Unique Identifier is a 128-bit value formatted as 8-4-4-4-12 hexadecimal characters. Version 4 UUIDs are randomly generated and have a collision probability low enough to treat as unique.

What is the difference between UUID v1 and v4?

Version 1 uses the current timestamp and your MAC address. Version 4 is randomly generated. Use v4 when you do not want to embed timing or hardware information in the ID.

Can two UUIDs ever be the same?

The probability is astronomically low for v4 UUIDs. With the randomness of 122 bits, you would need to generate billions of UUIDs per second for billions of years before a collision became likely.

Should I use UUIDs as database primary keys?

UUIDs work well as primary keys for distributed systems where you cannot coordinate a central counter. They do make indexes slightly larger and slower than sequential integers.