UUID Generator
Generate RFC 4122 compliant Version 4 UUIDs (Universally Unique Identifiers) or GUIDs. All calculations are executed client-side using hardware-level random entropy.
Generation Settings
What is a Version 4 UUID / GUID?
Universally Unique Identifier
A Universally Unique Identifier (UUID) or Globally Unique Identifier (GUID) is a 128-bit value used to uniquely flag records across distributed computing systems. Version 4 UUIDs are entirely random. Out of 128 bits, 6 bits are reserved for variant and version attributes, leaving 122 bits of random generation.
Negligible Collision Probability
With 122 bits of random entropy, there are $2^122$ (roughly $5.3 \times 10^36$) possible Version 4 UUIDs. The probability of a collision (generating the same ID twice) is mathematically negligible — so small that even if you generated 1 billion UUIDs per second for 100 years, the risk of a single collision is practically zero.
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