Generate cryptographically random UUID v4 values for databases, APIs, and apps. Choose how many to create (1–20), then copy one or all with a single click.
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Format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx (version 4, random). Uses crypto.getRandomValues().
Frequently Asked Questions
What is a UUID v4?
UUID v4 is a 128-bit identifier where most bits are random. The third group starts with “4” (version) and the fourth group’s first character is 8, 9, a, or b (variant). It is widely used for primary keys and session IDs.
How random are these UUIDs?
Random bytes come from crypto.getRandomValues(), the browser’s cryptographically secure API — not Math.random().
Can I generate more than one at a time?
Yes. Use the slider to create between 1 and 20 UUIDs per batch, then copy all at once.
Are UUIDs stored anywhere?
No. Generation runs entirely in your browser. Refreshing the page clears the list.
Need a password instead of an ID?
Use the Password Generator or Password Strength Checker for account security.
Is this tool free and does it work on mobile?
Yes on both counts. The UUID Generator on draft21 is completely free with no sign-up required and works on all devices.