UUID Generator for v4, v7 and ULID in Bulk, with a UUID Inspector

Pick a kind and count; press "Generate again" as often as you like. UUID v7 sorts by creation time, which makes a better database key than fully random v4. The box at the bottom inspects an existing UUID or ULID.

Part of the suite: Generators

Kind

How many (up to 1,000)

Uppercase With hyphens Wrap in { }

Result (one per line)

Inspect an existing UUID or ULID

FAQ

Can two UUIDs collide?

In theory yes, but UUID v4 has 122 random bits: you would have to make about 2.7 quintillion (2.7×10^18) to reach a 50% chance of one clash. In practice they are unique.

v4 or v7?

For database primary keys, v7 or ULID is better because they sort by time and cause fewer index page splits. If you do not want anyone to read the creation time from the id, use v4.

How is a ULID different from a UUID?

A ULID is 26 characters (a UUID is 36), sorts by time as plain text, and avoids the easily confused letters I L O U.

Help us improve

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