UUID/GUID Generator
Generate unique identifiers in multiple formats
Generated UUIDs
About UUIDs
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit standard identifier used to uniquely identify objects or entities. It's also known as GUID (Globally Unique Identifier) on Windows.
UUID Versions
- v1 (Time-based): Generated from timestamp and MAC address. Good for sequential ordering.
- v4 (Random): Generated from random numbers. Most commonly used for general purposes.
- nil: Special all-zeros UUID (00000000-0000-0000-0000-000000000000)
- max: Special all-ones UUID (ffffffff-ffff-ffff-ffff-ffffffffffff)
Use Cases
- Database primary keys
- Request tracking and correlation IDs
- User session identifiers
- Transaction identifiers
- Distributed system identification
- Asset and file naming
Format Examples
- Standard: 550e8400-e29b-41d4-a716-446655440000
- No Dashes: 550e8400e29b41d4a716446655440000
- Uppercase: 550E8400-E29B-41D4-A716-446655440000
- With Braces: {550e8400-e29b-41d4-a716-446655440000}
Probability of Collision
The probability of generating two identical UUIDs is virtually zero. With 128 bits, there are 2^128 possible UUIDs (approximately 5.3 × 10^36). Even if you generated 1 billion UUIDs per second, it would take trillions of years to generate all possible UUIDs.