UUID Generator
Generate RFC4122 v4 UUIDs locally.
Generate UUID v4 online — single or bulk, fully local
Generate cryptographically random UUID v4 identifiers instantly — one at a time or in bulk — with one-click copy. Uses your browser's crypto API, so the values are never transmitted or logged anywhere.
Frequently Asked Questions
- What is a UUID v4?
- A 128-bit identifier generated from random data, formatted as 8-4-4-4-12 hex digits. Version 4 means (almost) all bits are random rather than derived from time or hardware.
- Can two UUID v4 values collide?
- Theoretically yes, practically no: with 122 random bits, you would need to generate billions of UUIDs per second for decades before a collision becomes likely.
- UUID vs auto-increment ID — which should I use?
- UUIDs can be generated anywhere without coordination and do not leak record counts, but are larger and index less efficiently. Many systems use both: UUID externally, integer internally.
- What are UUID v1 and v7?
- v1 embeds a timestamp and MAC address (leaky, mostly legacy); v7 is a newer time-ordered random UUID that indexes efficiently in databases while staying unpredictable.