UUID Generator
Generate cryptographically random version-4 UUIDs (RFC 4122) for use as primary keys, file names, idempotency tokens, or any context needing a globally unique identifier. Donfig uses the browser's native crypto.randomUUID() where available and a getRandomValues fallback otherwise — both produce the full 122 bits of entropy required by the spec. Set the count and click Generate to produce up to 1000 UUIDs at once; copy each individually or all together. The Inspector below the generator parses any pasted UUID and reports its version and variant.
JavaScript is required to use the live tool. Please enable JavaScript and reload.
Frequently asked
What's the chance of a collision?
Astronomically low. With 122 bits of randomness, you'd need to generate roughly 2.7 quintillion UUIDs to have a 50% chance of any pair colliding (the birthday bound).
Why v4 instead of v1 or v7?
v1 leaks the MAC address and timestamp. v4 is purely random. v7 is timestamp-prefixed and sortable but newer; we'll add a v7 generator in a follow-up.
Can I include UUIDs in URLs?
Yes — the hyphenated form is URL-safe. For tighter URLs use a base64url encoding of the 16 raw bytes.