UUID / ULID Generator

UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify information in computer systems. It is standardized by RFC 4122 and has a format like 550e8400-e29b-41d4-a716-446655440000.

UUID v1 is generated based on the current timestamp and MAC address, making it time-ordered but potentially revealing system information. UUID v4 is randomly generated using cryptographically secure random numbers, making it more privacy-friendly and suitable for most use cases.

UUID v4 has 122 bits of randomness, making the probability of collision astronomically low (about 1 in 5.3×10^36). For all practical purposes, UUIDs are unique.

ULID (Universally Unique Lexicographically Sortable Identifier) is a 128-bit identifier that is sortable by creation time. Use ULID when you need unique IDs that can be sorted chronologically, such as database primary keys.