Leave empty to use the standard v4 format. x = lowercase hex, X = uppercase hex.
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About this tool
Create RFC 4122 version 4 universally unique identifiers entirely in your browser: generate one or many at once, switch between lowercase and uppercase, or use a custom template where x produces lowercase hex and X produces uppercase hex. Generation uses a cryptographically secure random source, and nothing is uploaded.
How to use
- Set how many UUIDs to generate (1–100).
- Optionally switch to uppercase, or enter a custom template (x = lowercase hex, X = uppercase hex).
- Click generate, then copy the results in one click.
Is my data uploaded anywhere?
No. UUIDs are generated entirely in your browser and nothing is uploaded.
Are the UUIDs cryptographically secure?
Yes. v4 UUIDs are generated with crypto.randomUUID / crypto.getRandomValues, a cryptographically secure random source.
What is the custom template feature?
In a template, x is replaced by a random lowercase hex digit and X by a random uppercase hex digit; any other characters are kept as-is. Leave it empty to use the standard v4 format.