UUID Generator
Generate RFC 4122 v4 UUIDs in bulk, right in your browser.
Generated with crypto.randomUUID() entirely in your browser. Nothing here is ever sent to a server.
5 UUIDs
For informational and educational purposes only — not professional or technical advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
What makes a UUID unique
A version 4 UUID is 122 bits of randomness formatted into the standard 8-4-4-4-12 hex layout — that's roughly 5.3 undecillion possible values, so collisions are astronomically unlikely even generating billions of them. They're the standard choice for database primary keys, distributed system identifiers, and anywhere you need a unique ID without coordinating with a central counter.
Frequently asked questions
How unlikely is a UUID v4 collision?
With 122 random bits, you'd need to generate roughly 2.7 quintillion UUIDs before a 50% chance of any collision — in practice, treated as effectively impossible for virtually any application.
What's special about the version and variant bits?
A UUID v4 has fixed bits that identify it as version 4 (random) and mark it as an RFC 4122 variant — that's why a v4 UUID always has a '4' in the same position and one of a few specific characters right after it.