UUID Generator

UUID Generator

Create RFC 4122 identifiers for databases, APIs, distributed systems, and tests.

Capabilities

• Version 1: Time-based UUID using the host identifier and clock sequence (per Python's uuid implementation).
• Version 3: Deterministic UUID from a namespace UUID plus a name string (MD5).
• Version 4: Random (or pseudorandom) UUID — the default for most new opaque IDs.
• Version 5: Deterministic UUID from a namespace UUID plus a name string (SHA-1).
• Batch generation: Request multiple UUIDs in one call (up to 100). Useful for fixtures or bulk allocation.
• Namespace UUIDs: Use built-in namespaces (dns, url, oid, x500) or supply a custom namespace as a full UUID string for versions 3 and 5.

Gotchas

• Version 1 and privacy: Time-based UUIDs can embed or relate to host identity (MAC-related node in typical implementations). Prefer v4 when you want no host signal in the identifier.
• Versions 3 and 5 are deterministic: The same namespace and name always produce the same UUID. Do not use them where unpredictability matters; use v4 instead.
• Version 4 is random: Each generated v4 is independent; suitable for session tokens and opaque IDs when combined with proper storage and entropy expectations.
• Batch + versions 3 or 5: Repeating the same namespace and name yields the same UUID each time, so a batch may contain identical values — that is expected for deterministic versions.