UUID Generator
Generate one or more cryptographically random UUID v4 identifiers. Uses your browser's built-in crypto API — results are never sent to a server.
Quantity
Click Generate to create UUIDs.
What is a UUID?
A Universally Unique Identifier (UUID) is a 128-bit label defined in RFC 4122. UUIDs are typically written as 32 hexadecimal digits in five groups separated by hyphens: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.
UUID version 4
Version 4 UUIDs are randomly generated. Two specific bits encode the version (4) and variant (RFC 4122). The remaining 122 bits are cryptographically random, giving a collision probability so low it is negligible for all practical purposes.
Why not Math.random()?
Math.random() produces pseudo-random numbers that are predictable given the internal state. This tool uses crypto.randomUUID() (and crypto.getRandomValues() as a fallback) — both are cryptographically secure and suitable for generating IDs used in databases, file names, and API resources.
Common use cases
- Primary keys in databases (especially distributed systems)
- Unique filenames for uploaded assets
- Idempotency keys for API requests
- Session or correlation identifiers