UUID Generator
Cryptographically secure UUID v4. Free. No signup.
Generate UUID v4 identifiers
Create cryptographically secure UUID version 4 identifiers. Generate one at a time or batch up to 1000 at once. Toggle hyphens, switch case, copy in one click. Uses your browser’s crypto.getRandomValues – real randomness, not Math.random.
Best for: database primary keys, request IDs, idempotency tokens, file naming, distributed systems where collision-free identifiers matter.
Click Generate to create UUIDs.
About UUID v4: 122 bits of randomness. Roughly 2^61 must be generated before the probability of a collision rises to ~50%. Safe for most application IDs without coordination. Note the fixed “4” in position 13 (version) and one of 8/9/a/b in position 17 (variant).