🆔UUID Generator

How to generate UUIDs

1. Pick a version. v4 is the usual random one; v7 is also random but starts with a timestamp, so ids sort in creation order and index well in a database.
2. Set how many you need and tick the formatting you want — uppercase, braces, no dashes or a urn:uuid: prefix.
3. Press Generate, then copy the list or download it as a text file. For v3 and v5, type a namespace and a name instead: the same input always produces the same id.

FAQ

Which version should I use?

Use v4 when you just need a unique id and nothing else. Use v7 for database primary keys — the leading millisecond timestamp keeps inserts at the end of the B-tree instead of scattering them. Use v5 when the same input must always map to the same id, for example deriving a stable id from a URL. v1 is legacy; this tool generates a random node id rather than reading a MAC address, so nothing about your machine is encoded.

Are these safe to use as secrets?

v4 and v7 take their randomness from crypto.getRandomValues, the browser's cryptographic generator, so a v4 has 122 random bits and is practically impossible to guess. Even so, treat ids as identifiers, not as passwords or session tokens — they usually end up in logs and URLs.

What are ULID and Nano ID?

ULID is a 26-character Crockford base32 string: 48 bits of millisecond time plus 80 random bits, lexicographically sortable and case-insensitive. Nano ID is a compact URL-safe random string — 21 characters give about the same collision resistance as a UUID v4 in a third fewer bytes.