UUID Generator
Create UUID v1, v4, and v7 for databases, APIs, and applications.
Generate unique identifiers (UUIDs) instantly.
What are UUIDs?
UUIDs are 128-bit identifiers designed to be unique without central coordination. They are ideal for database keys, distributed systems, and API identifiers.
UUID versions
- v1: Timestamp-based with node info; predictable order but may leak host details.
- v4: Random-based; collisions are astronomically unlikely with 122 bits of randomness.
- v7: Time-ordered; good for indexing while preserving randomness.
Best practices
- Use reputable libraries; avoid custom RNGs.
- Use v7 for write-heavy tables needing order-friendly IDs.
- Store UUIDs as binary in databases if supported for efficiency.
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FAQs
Are UUIDs guaranteed to be unique?
Practical collisions are astronomically unlikely for v4/v7 UUIDs. Uniqueness is sufficient for distributed systems without central coordination.
Which version should I use?
Use v7 for time-ordered IDs (better indexing), v4 for simple random IDs, and v1 only if you specifically need legacy time-based behavior.
Are UUIDs cryptographically secure?
UUIDs are not secrets. Do not use them as authentication tokens. For security, use random tokens with sufficient entropy and appropriate HMAC or signature schemes.