UUID / ULID Generator
Generate UUID v4 (random), UUID v7 (time-ordered) or ULID, one or many at once, using crypto.getRandomValues. Fully local, no Math.random.
Generated identifiers
How they are generated
UUID v4 16 bytes from crypto.getRandomValues. Version
4 is set in the high nibble of byte 6 and the RFC 4122 variant (10xx)
in the two high bits of byte 8. That leaves 122 random bits, formatted 8-4-4-4-12.
UUID v7 the first 48 bits are the Unix timestamp in milliseconds
(big-endian), then version 7, variant and 74 random bits. It is
time-ordered: two v7 values in a row compare as increasing.
ULID 26 characters in Crockford base32: 48 bits of time (10 chars) + 80 random bits (16 chars). Lexicographically sortable by its time prefix.
All randomness comes from the browser's CSPRNG. Math.random is never used
and nothing leaves your machine.
Identifiers are generated entirely in your browser. Nothing is downloaded or queried online.
Runs locally in your browser · no sign-up · nothing leaves your browser