UUID Generator
Generate random UUID v4 identifiers instantly. Choose format, bulk-generate up to 100, copy individually or all at once.
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit label standardised by RFC 4122. It is represented as 32 hexadecimal digits grouped in five sections separated by hyphens: 8-4-4-4-12.
UUIDs are designed to be unique across space and time without requiring a central registry, making them ideal for distributed systems, database primary keys, session tokens, and any situation where you need a unique ID without coordination.
UUID v4: random generation
Version 4 UUIDs are generated from random or pseudo-random numbers. Two bits are fixed (version and variant), and the remaining 122 bits are random, giving roughly 5.3 × 10³⁶ possible values.
The probability of generating a duplicate is astronomically low: you would need to generate about 2.7 × 10¹⁸ UUIDs before having a 50% chance of a single collision. This tool uses the browser's native crypto.randomUUID().
Format variants
All three formats represent the same 128-bit value.