Generate UUID
Generate unique identifiers. The randomness comes from the system’s cryptographic generator, not from Math.random, which promises nothing about being unpredictable.
Your text stays on your device: nothing is uploaded
Fully random: the right choice nearly always.
Advanced options
Result
How it works
A v4 UUID is made of random bytes: two identical ones do not happen, and you need not coordinate with anyone. It is the right choice nearly always. v7 exists for one specific case: used as a database key, it puts the instant in the first bits, so two generated in a row end up close together instead of scattered. ULID solves the same problem with an alphabet you can read aloud without ambiguity. Everything is generated here: nobody, us included, knows which numbers you got.
Frequently asked questions
- Does a v7 UUID reveal when it was created?
- Yes: the first twelve hex digits are the moment of creation, to the millisecond, and anyone who sees the identifier can read it. The same goes for ULID, in its first ten characters. If the identifier ends up in a public address and you would rather not reveal when the record was made, use v4.
- Are the identifiers in one list in order?
- For v7 and ULID, yes: each one is greater than the one before, even when hundreds are created in the same millisecond, so sorting them gives you exactly the order they appear in. This also holds from one list to the next. v4 is never ordered.
- Is it still a valid UUID in capitals or without dashes?
- It is the same identifier written differently, but the standard form is lowercase with dashes, and the standard asks for capitals to be accepted on input too. Remove the dashes or switch to capitals, under “Advanced options”, only if whatever receives them wants that. ULID is always uppercase without dashes, so those two options disappear for it.
- Why does the list change when I touch an option?
- Every change, to the number, the kind or the format under “Advanced options”, generates a new list from scratch: it does not transform the one you see. If you have already used some identifiers, copy them before changing anything. Without typing anything you get 5; the maximum is 500 at a time, and if you need more, copy them and generate another list.
What you paste is never uploaded. Anywhere.
The text you type stays in your browser’s memory: no request goes out while you type. You can paste something confidential.
- Processed locallyEverything happens on this page.
- Nothing to upload, nothing to wait forNothing to upload, no waiting.
- Nothing to deleteWe keep nothing: nothing reaches us.