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Generate random UUIDs
Generates version 4 UUIDs using the browser's own crypto.randomUUID(), which draws from the same cryptographically secure source your operating system uses.
UUID v4 — random, from crypto.randomUUID()
How to use it
- 1Set how many UUIDs you need.
- 2Press Generate.
- 3Copy the list from the output panel.
Frequently asked questions
- Are these safe to use in production?
- Yes. They come from the browser's own crypto.randomUUID(), which draws on the same cryptographically secure random source your operating system gives every other application. It is not a Math.random() imitation.
- What makes a UUID version 4?
- 122 random bits, with the remaining 6 fixed to mark the version and variant. Nothing about the machine, the time or the sequence is encoded, which is exactly why two of them never need to be coordinated to stay distinct.
- Can two generated UUIDs ever collide?
- In theory. In practice you would need to generate around 2.7 × 10¹⁸ of them for a one-in-a-billion chance, so a collision is not something to design around.
- Should I use a UUID as a database primary key?
- It works and it lets clients mint ids without a round trip, at the cost of a wider key and random insert order, which fragments a B-tree index. If that matters, keep a sequential integer as the internal key and expose the UUID externally, or use a time-ordered id format.