UUID Generator
Generate universally unique identifiers (UUIDs)
Generate UUIDs
Create unique identifiers for your applications
History & RFCs
UUIDs (Universally Unique Identifiers) were standardized in RFC 4122 and updated in RFC 9562. Different versions define how bits are produced (time, names, random, etc.).
Version 1 (time-based)
Time-based UUID derived from a timestamp and node identifier. Useful for ordering but may leak timing or device information.
Version 4 (random)
Random-based UUID (preferred for most apps). With secure randomness it offers low collision probability and no sequencing data.
Nil UUID
A special all-zero UUID value, typically used as a placeholder or sentinel.
Notes
- • This tool’s “v1” is a browser-friendly v1-like surrogate (NOT RFC 4122 v1).
- • v4 generation uses Web Crypto when available for RFC-compliant randomness.
- • Avoid exposing sensitive data via sequential identifiers; UUIDs help mitigate that.
- • Prefer v4 unless you have a strong reason to need time-ordering or namespacing.