UUID / GUID Generator
Generate RFC 4122 Version 4 UUIDs and GUIDs in bulk instantly.
How to use this tool & FAQs
Click any question below to expand its guide and answer
About RFC 4122 Version 4 UUIDs
A Universally Unique Identifier (UUID) or Globally Unique Identifier (GUID) is a 128-bit label used to uniquely identify records, entities, and database primary keys across distributed systems without requiring a central coordinator. Version 4 UUIDs are generated using 122 bits of cryptographically strong pseudo-random numbers.
Format & collision probability
Standard UUIDs take the canonical 36-character hexadecimal form xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, where the 13th digit is fixed to 4 (version) and the 17th digit is restricted to 8, 9, a, or b (RFC 4122 variant 1). The probability of a duplicate collision among billions of randomly generated v4 UUIDs is effectively zero (1 in 2^122, or roughly 1 in 5 sextillion).
Local generation
All UUIDs are generated directly in your browser using the native Web Cryptography crypto.randomUUID() API. Nothing is recorded or uploaded to external servers.