UUID Generator
Generate universally unique identifiers locally in your browser using the cryptographically secure Web Crypto API. Choose random v4 or time-ordered v7, singly or in bulk.
How it works
UUID v4 fills 122 bits with random data from the Web Crypto API. UUID v7 (RFC 9562) replaces the first 48 bits with a Unix millisecond timestamp, keeping 74 random bits — ids remain unique but become sortable by creation time, which is why v7 is now the recommended default for database keys.
Everything is generated on your device; no server ever sees or logs the ids.
FAQ
What's the difference between UUID v4 and v7?
v4 is 122 bits of pure randomness. v7 puts a millisecond timestamp in the first 48 bits, so ids sort by creation time — which makes database indexes on UUID primary keys dramatically faster.
Are these UUIDs cryptographically secure?
Randomness comes from the browser's Web Crypto API (crypto.getRandomValues / crypto.randomUUID), the same source used for key generation. They are unpredictable, but UUIDs are identifiers, not secrets — don't use them as passwords or tokens.
Can two generated UUIDs collide?
The probability is astronomically small: you'd need to generate about 2.7 quintillion v4 UUIDs to reach even a 50% chance of one collision.