UUID Generator

Versions 4 and 7, with structure breakdown and bulk export.

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit value used to label information without a central authority. Because the space is so large, two independently generated UUIDs are effectively guaranteed never to collide, which makes them ideal for database keys, distributed systems, and request tracing.

UUIDs are written as 32 hexadecimal digits in five hyphenated groups, the 8-4-4-4-12 layout. Two positions are reserved: the version nibble and the variant bits.

xxxxxxxxtime / random
-
xxxxrandom
-
Vxxxversion
-
Nxxxvariant
-
xxxxxxxxxxxxnode / random

Version 4 fills almost every bit with randomness (122 random bits). It is the everyday default when you just need a unique value and do not care about ordering.

Version 7 places a 48-bit Unix millisecond timestamp at the front, so the IDs sort by creation time. That ordering makes v7 friendlier to database indexes than the fully random v4, while still carrying plenty of randomness to stay unique.