ID Generator

Generate UUIDs (v1, v4, v7), ULIDs, and nanoids — in bulk, copy-on-click. Everything is generated in your browser.

Type

How many

Which ID should I use?

v4 for random, v7 for sortable DB keys, ULID/nanoid for compact + URL-safe.

A UUID is a 128-bit identifier. v4 is fully random — the everyday default when you just need uniqueness. v7 embeds a millisecond timestamp in the high bits, so v7 IDs sort chronologically — ideal for database primary keys (better index locality than v4). v1 is the legacy time + MAC-based scheme, largely superseded by v7.

ULID packs a 48-bit timestamp + 80 bits of randomness into a 26-character Crockford base32 string — sortable and case-insensitive. nanoid is a compact, URL-safe random string (21 characters by default) popular when you want something shorter than a UUID in URLs. All of these are generated locally using your browser's cryptographic random source — nothing is requested from or sent to the server.

Frequently asked

Are UUIDs guaranteed to be unique?

Not guaranteed, but collisions are astronomically unlikely. A v4 UUID has 122 random bits, so you would need to generate billions before a collision becomes plausible.

UUID v4 or v7 — which should I use?

v4 is fully random, best for opaque identifiers. v7 is time-ordered, so it sorts chronologically and indexes far better as a database primary key.

What about ULID and nanoid?

ULIDs are sortable like v7 but more compact and URL-safe; nanoids are short random URL-safe strings. Use them when you want something shorter than a UUID.