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UUID/ULID Generator

Generate bulk UUIDs (v4) and ULIDs for your applications.

5
Generated Identifiers
Output will appear here…

Frequently Asked Questions

What is a UUID v4?

A Universally Unique Identifier (UUID) v4 is a 128-bit number used to uniquely identify information in computer systems. Version 4 is generated using random or pseudo-random numbers.

What are the odds of a collision?

The probability of two UUID v4s being the same is infinitesimally small. Even if you generated 1 billion UUIDs every second for 100 years, the probability of creating a duplicate would be approximately 50%.

What is a ULID and when should I use one?

A ULID (Universally Unique Lexicographically Sortable Identifier) is a 26-character identifier that starts with a 48-bit millisecond timestamp followed by 80 bits of randomness, encoded in Crockford base32. Because IDs generated later sort after earlier ones, ULIDs make excellent database keys where insert order matters — unlike UUID v4s, which index in random order.