Tools

UUID v4 generator

Create version 4 (random) UUIDs using crypto.randomUUID() when available, with a secure fallback. Up to 100 at once.

Options

Number of UUIDs (1–100): 5

FormatUppercase hexInclude hyphens

Results

Click Generate to create UUIDs.

FAQ

What is a UUID v4?

Version 4 UUIDs are 128-bit identifiers where most bits are random, with version and variant bits set per RFC 4122. They are useful for client-side IDs, logs, and test data.

Is the fallback as secure as randomUUID?

The fallback uses crypto.getRandomValues to fill 16 bytes, then sets the version and variant fields. Avoid Math.random for UUIDs; this tool does not use it.

Are these guaranteed unique?

Collisions are astronomically unlikely for random v4 UUIDs, but not mathematically impossible. For database primary keys, still use your engine's uniqueness constraints.