UUID Generator
UUID Generator
About UUID Generator
Generate random UUID v4 identifiers online with our free uuid generator. Create universally unique identifiers for databases, APIs, session tokens, and distributed systems. No central authority is needed — each UUID is practically guaranteed to be unique across space and time.
Example
Sample UUID v4
550e8400-e29b-41d4-a716-446655440000Format
8-4-4-4-12 hex digitsWhy Use UUID Generator?
- Guaranteed uniqueness — The probability of collision is astronomically low (about 1 in 5.3 × 10^36).
- No central authority — Generate UUIDs anywhere without coordination or a central server.
- Database-friendly primary keys — Ideal for distributed databases, replication, and offline-first apps.
UUID Generator FAQs
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier that is practically guaranteed to be unique across space and time. The most common format is version 4, which uses random numbers.
Are UUIDs truly unique?
While not mathematically guaranteed, the probability of generating two identical v4 UUIDs is astronomically low — about 1 in 5.3 × 10^36. For all practical purposes, they are unique.
When should I use UUIDs?
Use UUIDs as primary keys in distributed databases, for session identifiers, API request tracking, file naming, and anywhere you need a unique ID without a central authority.
What is the format of a UUID v4?
A UUID v4 follows the pattern xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where x is any hex digit and y is one of 8, 9, a, or b. The 4 indicates version 4.
Can I use UUIDs as database primary keys?
Yes. UUIDs are widely used as primary keys in distributed databases like PostgreSQL, MongoDB, and DynamoDB because they can be generated independently without coordination.