UUID Generator (v4)
Generate cryptographically random version 4 UUIDs, one at a time or in bulk.
Click Generate to create UUIDs.
UUIDs are generated locally using your browser's secure random source.
How to use UUID Generator
- 01Choose how many UUIDs you need, from one to a hundred.
- 02Toggle uppercase or remove hyphens if your system expects that format.
- 03Copy a single value or the whole list.
About UUID Generator
A version 4 UUID is 122 random bits with six bits reserved for the version and variant markers. That is enough space that collisions are not a practical concern: you would need to generate billions of values before the chance of a duplicate became meaningful.
These are produced with your browser's cryptographic random number generator, not Math.random, so they are suitable as database keys and correlation identifiers. They are not secrets — a UUID identifies something, it does not authorize anything.
Frequently asked questions
- Are these UUIDs unique?
- In practice, yes. Version 4 UUIDs use 122 random bits, so accidental duplicates are vanishingly unlikely.
- Are they generated on a server?
- No. Everything happens in your browser using the Web Crypto API.
- Can I use a UUID as a password?
- It is random enough, but UUIDs are designed to be shared as identifiers, so use a password generator for secrets.
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