UUID Generator
Generate cryptographically secure, random (version 4) UUIDs — one at a time or a thousand at once. Runs entirely in your browser; nothing is sent anywhere.
How to use the UUID generator
- Set how many UUIDs you need (1 to 1,000) and click Generate.
- Toggle Uppercase or Remove hyphens if your use case needs a specific format.
- Use Copy all to copy the whole list, or Download .txt to save it.
Common uses
- ✓ Database primary keys and distributed-system record IDs
- ✓ Idempotency keys for API requests
- ✓ Test fixtures and mock data in unit tests
- ✓ Session or correlation IDs for request tracing/logging
FAQs
What is a UUID?
A Universally Unique Identifier is a 128-bit value, usually written as 32 hex digits in five groups (8-4-4-4-12), designed to be unique across systems without any central coordination. This tool generates version 4 (random) UUIDs, the most common type.
How random are these, really?
Every UUID is generated with the browser's crypto.randomUUID() (or crypto.getRandomValues() as a fallback) — a cryptographically secure random number generator, not Math.random(). With 122 random bits in a v4 UUID, collisions are astronomically unlikely even across billions of IDs.
Can I use these as database primary keys?
Yes, UUIDs are commonly used as primary keys specifically because they can be generated independently on multiple machines or clients with no risk of collision, unlike auto-incrementing integers. The trade-off is index locality — random UUIDs can fragment certain database indexes more than sequential IDs, which matters at very large scale but rarely for typical applications.
Why remove the hyphens?
Some systems and column formats expect a bare 32-character hex string without hyphens. The "Remove hyphens" option gives you that format without any manual find-and-replace.