UUID Generator
Generate RFC 4122 version 4 UUIDs with the browser's own crypto, one at a time or up to a thousand at once.
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What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier standardized by RFC 4122. Version 4 UUIDs are generated using cryptographically secure random numbers, making collisions practically impossible — the probability of generating two identical UUIDs is about 1 in 5.3 × 1036.
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx The 4 indicates version 4. The y position is the variant (8, 9, a, or b). This generator uses crypto.randomUUID() — the Web Crypto API — for secure, browser-native UUID generation. All processing happens entirely client-side; nothing is sent to any server.
Common UUID Use Cases
- Database primary keys (PostgreSQL, MongoDB)
- API request IDs and correlation tokens
- Distributed systems — unique IDs without coordination
- Session tokens and temporary identifiers
- File naming to prevent collisions