🆔 UUID Generator
Generate unique UUIDs for development
How UUID v4 Generation Works
Formula
Format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
- 1128 random bits are generated using a cryptographically secure random function.
- 2Bits 48–51 are set to 0100 (version 4 identifier).
- 3Bits 64–65 are set to 10 (RFC 4122 variant).
- 4The 128 bits are formatted as 32 hex digits with hyphens: 8-4-4-4-12.
- 5The result is a globally unique identifier with ~5.3 × 10³⁶ possible combinations.
About UUID Generator
Generate unique UUIDs (v4) instantly. Create single or bulk universally unique identifiers for databases, APIs, and development. Copy with one click.
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify objects in computer systems. Version 4 UUIDs are randomly generated.
Can two UUIDs ever be the same?
Theoretically yes, but the probability is astronomically low — about 1 in 5.3 × 10³⁶. You'd need to generate 1 billion UUIDs per second for 85 years to have a 50% chance of a collision.
What is UUID v4 used for?
Database primary keys, API request identifiers, session tokens, file names, distributed system IDs — anywhere you need a unique identifier without a central authority.