How to generate UUIDs
- Set how many you need (1–1,000) and toggle uppercase or hyphen-free formats if your system requires them.
- Click ↻ Generate for a fresh batch — every UUID comes from your browser's cryptographic randomness.
- Copy all and paste into your code, database seed or spreadsheet.
Where UUIDs are used
UUIDs solve the "I need an ID and can't check a central counter" problem: database primary keys in distributed systems, API request IDs, file names that must never collide, correlation IDs in logs, and test fixtures. The v4 variant generated here is pure randomness — 122 random bits — which makes collisions so unlikely they're treated as impossible in practice. The no-hyphen option produces the 32-character format some databases and legacy systems expect.
Frequently asked questions
What is a version 4 UUID?
A 128-bit identifier generated from random data, formatted as 32 hex characters like 550e8400-e29b-41d4-a716-446655440000. With 122 random bits, the chance of two ever colliding is negligible.
Are these UUIDs truly random and unique?
They're generated with your browser's cryptographic random number generator — the same quality of randomness used for security keys. Uniqueness is statistical: you'd need billions per second for centuries to expect a collision.
Can I generate UUIDs in bulk?
Yes — up to 1,000 at a time, one per line, ready for a spreadsheet, SQL script or test fixture. Everything is generated locally.