Generate universally unique identifiers (UUIDs) instantly. Create RFC 4122 compliant UUIDs for database keys, session IDs, and distributed systems.
UUIDs (Universally Unique Identifiers) are 128-bit identifiers that are practically guaranteed to be unique without central coordination. UUID v4 uses random numbers for generation, making collision probability astronomically low (about 1 in 2.7×10^18). They are widely used for database primary keys, session tokens, and distributed system identifiers.
UUID v4 = xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx (where y ∈ {8,9,a,b})UUID v4 follows the format 8-4-4-4-12 hexadecimal digits. The version digit is always "4" at position 13, and the variant digit (position 17) starts with 8, 9, a, or b. All other digits are randomly generated, providing 122 bits of randomness.
| Input | Output |
|---|---|
| Generate 1 UUID | f47ac10b-58cc-4372-a567-0e02b2c3d479 |
| Generate 1 UUID | 6ba7b810-9dad-11d1-80b4-00c04fd430c8 |
| Generate 1 UUID | 550e8400-e29b-41d4-a716-446655440000 |