UUID Generator
Generate random UUID v4 identifiers, one at a time or in batches, with the browser's crypto API.
How they're generated
It uses crypto.randomUUID(), the browser's native function for generating unique identifiers with cryptographically secure randomness — not Math.random(), which isn't meant for this.
Privacy
The generation happens entirely in your browser. There's no backend behind it — the UUIDs aren't stored or sent anywhere.
When to use a UUID v4
A UUID has the format 8-4-4-4-12 hexadecimal characters (3f2b…, for example).
- Unique identifiers in databases with no coordination between systems.
- Unpredictable file names or tokens (for secrets, use a dedicated library).
- Tests and sample data.
Which UUID version it generates
It generates UUID v4 identifiers, the most common version: built from random numbers (not from the clock or the device's network address), so they reveal nothing about when or where they were generated.