Generate UUIDs
Validate UUID
UUID Versions
Version 1
Based on timestamp and MAC address. Sortable by creation time but may leak device info.
Version 4
Randomly generated. Most commonly used. 122 bits of randomness = 5.3 x 10^36 possible values.
Version 5
Generated from namespace + name using SHA-1. Deterministic - same input = same UUID.
Nil UUID
00000000-0000-0000-0000-000000000000 - Special case representing no value.