Which UUID versions are supported?

v4 (random), v7 (Unix time + random, time-ordered), v5 (name-based SHA-1), and v3 (name-based MD5).

Yes. v4/v7 randomness uses the Web Crypto API. Everything runs locally in your browser.

What are namespaces for v3/v5?

They scope the name when generating v3/v5. We include DNS, URL, OID, X.500 presets and a custom input.

v7 preserves lexical/time ordering for easier indexing while keeping strong randomness for uniqueness.

Generate RFC-compliant UUIDs entirely in your browser. Choose version, formatting, namespaces for v3/v5, and create many at once.

Need a different utility?

UUID

Version: — Variant: —

Version

Count

Output format

Separator (list)

Default newline (\n)

v4: purely random (Web Crypto).
v7: time-ordered (48-bit ms timestamp + randomness) for better DB indexing.
v3/v5: name-based with namespace + name (MD5/SHA-1). Same (namespace, name) ⇒ same UUID.

Is everything local?

Yes. We use the Web Crypto API for randomness and hashing — nothing is uploaded.

Do v3/v5 need special inputs?

Provide a namespace (pick a preset or paste a UUID) and a name (like a domain). Output is deterministic.