UUID generator
Generate one or a thousand UUIDs, version 4 (random) or version 7 (time-ordered).
v4 or v7?
- Version 4 is 122 random bits. It's the most common choice and reveals nothing about when it was made.
- Version 7 (RFC 9562, 2024) starts with a 48-bit millisecond timestamp followed by random bits, so new IDs sort after old ones. That keeps database indexes compact and fast, which makes v7 a great choice for primary keys.
Will two UUIDs ever collide?
For v4, you'd need to generate about 2.7 quintillion (2.7 × 1018) UUIDs for a 50% chance of a single duplicate. In practice, collisions only happen with broken random number generators. stackbite uses your browser's cryptographic generator.
Questions
Is a GUID the same as a UUID?
Yes. GUID is Microsoft's name for the same 128-bit identifier.
Can I generate UUIDs without hyphens?
Yes. Untick "Hyphens" to get the 32-character form.