UUID Knowledge Base

The complete unified theory of Universally Unique Identifiers.
From bit-level anatomy to database optimization.

Overview & Anatomy

Understand the 128-bit structure, variants, and bit layout.

From Apollo NCS (1980s) to the modern RFC 9562.

Deep dive into the philosophy, physics, and history of identifiers.

Deep dive into v1, v4, v6, v7, and custom vendor formats.

Side-by-side comparison of uniqueness and performance.

Best practices for MySQL, PostgreSQL, and URL shortening.

Copy-paste generation examples in 10+ languages.

Benchmarks for database insertion and collision probability.

Common questions about collisions, security, and usage.