UUID v3 Generator
Generate name-based UUID v3 identifiers using MD5.
Generate deterministic UUID v3 identifiers from a namespace and name (MD5). Free, offline, runs in your browser. Read more Show less
What is UUID v3?
A UUID v3 is a deterministic (name-based) UUID. Given a namespace UUID and a name, it produces the same UUID every time. This is useful for generating stable identifiers from names, such as a unique ID for a URL or a package.
The construction is: hash the namespace bytes followed by the name bytes with MD5, take the first 16 bytes, set the version nibble to 3 and the variant bits, and format as a UUID. Because MD5 is used, v3 is considered legacy. Prefer v5 (SHA-1) for new systems.
FAQ
v3 vs v5
Both are deterministic. v3 uses MD5, v5 uses SHA-1. For new work, prefer v5. v3 exists for compatibility with systems that already use it.
What are the standard namespaces?
RFC 4122 defines four: DNS, URL, OID, and X500. Pick one based on what the name represents.
Is the same UUID always produced?
Yes, for the same namespace and name. That is the entire point: UUID v3/v5 values are stable across systems.