Generators tool
UUIDs, in bulk.
Version 4 identifiers from your browser's cryptographic random source. Up to five hundred at a time, formatted however your system wants them.
- Free, no sign-up
- Nothing is uploaded
- No watermark, no limits
UUID v4 generator
FreeWorth knowing
How to get this right.
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01
What version 4 actually guarantees
A v4 UUID is 122 random bits with six bits fixed to mark the version and variant. It carries no timestamp, no MAC address and no sequence — which is exactly why it is safe to expose in a URL. Nothing about it reveals when or where it was made.
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02
Collisions are not a practical concern
You would need to generate around a billion UUIDs a second for a century to reach a 50% chance of one collision. If you see duplicates in production, the cause is a bug in how they are assigned, not the random source.
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03
They make poor primary keys in a large table
Random UUIDs scatter inserts across a B-tree index, which fragments it and hurts write throughput at scale. If that matters, keep an auto-increment key internally and expose a UUID externally, or look at a time-sortable format like UUID v7.
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