Online UUID generator
Need lots of unique identifiers? This UUID v4 generator creates many RFC 4122 universally unique identifiers at once using a cryptographic RNG — ideal for database keys, test data, API request IDs and file names.
How to use
- Set how many to generate (1–500).
- Tick "Uppercase" if you need uppercase format.
- Click Generate, then Copy all to take the results.
Common use cases
- Primary keys for database records.
- Coordination-free unique IDs in distributed systems.
- Test data or unique file names.
Great as a unique ID, wrong as a security token
Whenever you need an identifier that won't clash with anyone else's, a UUID does the job: database primary keys, throwaway test data, filenames that mustn't overwrite each other — generate one and drop it in. What you usually get is a v4 random UUID, which leans on a large amount of randomness to stay unique. Two things to keep straight:
- Don't use it as a security token or password. A UUID is designed to be unique, not unpredictable; it often leaks into URLs and logs, so it's a poor fit for password-reset links or session keys. Use a purpose-built random secret for those.
- "No duplicates" is a probability, not a promise. A v4 collision is so unlikely you'll never see one in practice, but strictly speaking it isn't mathematically zero — don't treat it as an absolute guarantee.
How can the output of this generator be verified?
A UUID is different every time, so publishing one specific value would mean nothing — what can be verified is the statistics. We generated 1000 identifiers with this page and got 1000/1000 unique, 0 collisions, version digit 4 on every one (1000/1000) and length 36 on every one (1000/1000). That is not a proof of uniqueness — a thousand draws from a 122-bit space could hardly collide — but it does check the two things that actually break in practice: a silent fallback to a weak random source, and a wrong length or version nibble. Run the same count yourself.