Generate UUIDs
Validate UUID
UUID Versions
Version 1
Time-based. This tool uses a random node id with the RFC 4122 multicast bit set, so no MAC address is exposed. Note: v1 strings do not sort in creation order — use v7 for that.
Version 4
Randomly generated. The most common choice. 122 bits of randomness = 5.3 × 1036 possible values.
Version 5
Deterministic: a namespace UUID plus a name, hashed with SHA-1. The same namespace and name always produce the same UUID.
Version 7
Time-ordered (RFC 9562): a 48-bit millisecond timestamp followed by random bits, so the strings sort by creation time. A good default for database keys.
Nil UUID
00000000-0000-0000-0000-000000000000 — special case representing no value.