UUID Generator
Random v4 UUIDs, generated locally, one at a time or in bulk.
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How it works
To generate a UUID, this page creates one automatically using your browser’s crypto.randomUUID() — adjust the count above to generate up to 100 at once, with optional uppercase and no-hyphen formatting.
A UUID (universally unique identifier) is a 128-bit value, conventionally written as 32 hex digits split into five groups. A version 4 UUID sets a few fixed bits to mark its version and variant and fills the rest — 122 bits — with random data, which is what this tool generates via crypto.randomUUID(), the same generator function browsers expose natively for this exact purpose.
The collision odds are the whole point of the format: with 122 random bits, you would need to generate roughly a billion UUIDs every second for about 85 years before the probability of any collision reached 50%. That is why UUIDs work as database primary keys or distributed identifiers without any central coordinator handing out numbers.
Formatting options here only change how the same value is written, not what it is: hyphens can be stripped for contexts that want a plain 32-character string, and letters can be uppercased. Neither changes the underlying bits or the randomness guarantee.
FAQ
Are these UUIDs sent to a server or logged anywhere?
No. They are generated by crypto.randomUUID() directly in your browser and never transmitted. The live network monitor on this page confirms nothing is sent.
What UUID version does this generate?
Version 4 — fully random except for the fixed version and variant bits the format requires. This is the most common UUID version for general-purpose identifiers.
Can two of these UUIDs ever collide?
In theory, yes — but with 122 random bits the odds are astronomically small: you would need billions of UUIDs generated per second for decades before a collision became likely.