Generate a value

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Where does the randomness come from?

A UUID v4's uniqueness guarantee rests entirely on its 122 random bits being genuinely unpredictable; a UUID generated from a weak or predictable random source narrows the collision resistance the format is supposed to provide.

This tool seeds its random bits from Galactropy's physical SDR entropy pool before formatting the standard 8-4-4-4-12 hex layout with the required version and variant bits set.

⚠ Cryptographic notice

UUIDs are identifiers, not secrets: don't use a UUID v4 as an authentication token or session secret; use the token generator for that instead.

Frequently asked questions (FAQ)

Can two generated UUIDs ever collide?

Practically, no: with 122 random bits, you'd need to generate roughly a billion UUIDs per second for about 85 years before a 50% chance of a single collision.

Is the output valid RFC 4122 format?

Yes: each UUID follows the standard 8-4-4-4-12 hyphenated hex layout with the version (4) and variant bits set correctly.