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Generate universally unique identifiers in bulk: classic v4 (122 bits of cryptographic randomness) or v7, the newer time-ordered format whose leading timestamp makes IDs sort by creation time — a meaningful win for database index locality. Format options cover the common variants: uppercase, and dash-free for systems that store the 32 hex characters raw.
Frequently asked questions
Can two generated UUIDs ever collide?
Theoretically yes, practically no: v4 has 2¹²² possibilities. You'd need to generate a billion UUIDs per second for ~85 years to reach a 50% chance of one collision. Systems treat them as unique without checking.
When should I use v7 instead of v4?
When the ID becomes a database primary key. v4's randomness scatters inserts across the index; v7's timestamp prefix keeps recent rows together, which measurably improves insert performance on B-tree indexes. v4 remains right when you don't want IDs to leak creation time.
Are these UUIDs generated securely?
Yes — both versions draw from the browser's cryptographic RNG (crypto.randomUUID / getRandomValues), locally on your device. None are logged or sent anywhere.