UUID Generator
Generate random UUIDs, one or in bulk. Version 4 (random) and version 7 (time-ordered), 100% in your browser.
Click the UUID to copy it
Bulk generate
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit value written as 32 hexadecimal digits in five groups, for example xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx. UUIDs let you generate identifiers on any machine, at any time, without a central authority, and still be practically certain they never clash.
Can two UUIDs collide?
In theory yes, in practice no. A version 4 UUID contains 122 random bits, so there are 2^122 (about 5.3 undecillion) possible values. You would need to generate about a billion UUIDs per second for roughly 85 years to reach even a 50% chance of a single collision.
v4 vs v7, which one to pick?
Version 4 is fully random. Use it when you just need a unique ID and ordering does not matter.
Version 7 (RFC 9562) starts with a 48-bit Unix millisecond timestamp followed by random bits, so values sort by creation time. That makes it the better choice for database primary keys and indexes, where random v4 keys cause index fragmentation.
Everything runs in your browser using the cryptographically secure Web Crypto API. Nothing is sent anywhere.
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