About UUID v5 / v3 Generator

UUID v5 / v3 Generator makes UUIDs that are a function of a namespace UUID and a name, so the same inputs always give the same UUID.

Version 5 uses SHA-1, version 3 uses MD5. It also parses any UUID and reports its version and variant. It runs in your browser.

How to use it

  1. Pick a namespace: DNS, URL, OID, X.500, or paste your own UUID.
  2. Enter the name, for example a domain or a path.
  3. Copy the v5 or v3 UUID, or paste a UUID into the inspector.

Common questions

When should I use v5 over v4?

Use v5 when you want the UUID to be reproducible from a known name, for example an ID derived from a URL. Use v4 for a purely random ID.

Is v3 safe to use?

It works and is part of the spec, but it relies on MD5. Prefer v5 unless you must match an existing v3 scheme.

What is a namespace?

A UUID that scopes the name so the same name in two namespaces produces different UUIDs. The standard ones for DNS, URL, and so on are built in.

Does anything leave my browser?

No. The tool runs entirely on this page.