UUID Generator

A UUID (Universally Unique Identifier) is a 128-bit identifier that is unique across space and time. It's formatted as 8-4-4-4-12 hexadecimal digits: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. UUIDs are used as database primary keys, session identifiers, and distributed system IDs.

UUID v1 is time-based and includes the current timestamp and your MAC address, making it sortable by creation time but potentially exposing machine identity. UUID v4 is randomly generated, providing better privacy. UUID v7 is newer and combines random data with a millisecond timestamp for sortability without MAC address exposure.

Technically yes, but practically no. With 122 random bits, you'd need to generate over 1 billion UUIDs per second for 85 years to have a 50% chance of a single collision. For all practical purposes, v4 UUIDs are unique.

UUID v7 (RFC 9562) combines a millisecond Unix timestamp with random bits. This makes UUIDs sortable by creation time while still being globally unique. It's ideal for database primary keys where sort order matters for performance.

Most databases support UUID as a primary key type. In PostgreSQL: `id UUID PRIMARY KEY DEFAULT gen_random_uuid()`. In MySQL: `id CHAR(36) PRIMARY KEY`. For best performance with sequential inserts, use UUID v7.

Both formats are valid. The UUID standard uses lowercase letters (a-f). Some systems prefer uppercase. Our generator provides both and lets you copy either format.