Free UUID Generator
Generate random, unique RFC 4122 compliant UUID v4 (Universally Unique Identifier) strings in bulk. Fast and secure client-side generation.
What is a UUID (and GUID)?
A UUID (Universally Unique Identifier) is a 128-bit label used for information in computer systems. Microsoft systems commonly refer to them as GUIDs (Globally Unique Identifiers). A canonical UUID is represented by 32 hexadecimal digits displayed in five groups separated by hyphens (format: 8-4-4-4-12, total 36 characters).
UUIDs are designed to guarantee uniqueness across space and time, removing the need for a central coordinating registration authority.
UUID Version 4 vs. Other Versions
Different UUID versions specify different generation mechanisms:
- Version 1: Time-based and node/MAC address identifier.
- Version 3: Name-based using MD5 hashing.
- Version 4: Completely randomly generated values (utilizing 122 bits of entropy).
- Version 5: Name-based using SHA-1 hashing.
This tool generates UUID v4 strings using browser-native cryptographically secure pseudo-random values.