UUID Generator

v4 (random), v7 (time-ordered), v1, NIL — up to 1000 at once

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit value that creates globally unique identifiers without a central authority. It is standardized in RFC 4122 (classic) and RFC 9562 (v6/7/8). It is represented as 32 hexadecimal digits in five dash-separated groups.

Which UUID version do I need?

  • v4: random, safe, most common choice for database IDs
  • v7: time-ordered, ideal for database indexes and chronological sorting
  • v1: timestamp + MAC address (legacy, may leak metadata)
  • NIL: all bits zero — placeholder for 'no UUID'

How random are UUIDs?

In UUIDv4, 122 of 128 bits are random (the other 6 encode version and variant). The collision probability is astronomically small: even at one billion UUIDs per second for 85 years, the chance of a collision stays below 50%. In practice, UUIDs are treated as collision-free. This tool uses the Web Crypto API (crypto.getRandomValues) for cryptographically strong randomness.