Generate RFC 4122 version 4 UUIDs
A tool that generates RFC 4122 version 4 UUIDs — 128-bit identifiers random enough that two generated anywhere, by anyone, are never expected to collide, with no central registry required.
Set how many you need, up to 100.
Toggle any formatting options.
Click Generate, then copy one or all.
A 128-bit value that's almost entirely random, following the RFC 4122 layout with a small number of fixed bits that mark it as version 4 and identify it as a UUID at all. Because it's random rather than based on a counter or timestamp, two systems can generate UUIDs independently with no risk of collision and no need to coordinate with each other.
Yes. GUID (Globally Unique Identifier) is Microsoft's name for the same format that's called UUID elsewhere — identical structure and the same 36-character hyphenated form, just different terminology depending on the ecosystem you're working in.
No, only version 4. It doesn't generate v1 (built from a timestamp and MAC address), v5 (deterministic, derived from a namespace and name so the same input always produces the same UUID), or v7 (time-ordered, increasingly popular for database primary keys because it sorts naturally and indexes better than v4).
Yes, in any modern browser. UUIDs come straight from crypto.randomUUID, a cryptographically
secure random source built into the browser. A weaker Math.random()-based fallback only
exists for very old browsers that lack that API, which is effectively no browser in current use.
Set the quantity up to 100 and click Generate for a full batch at once, each with its own Copy button, or use Copy All to grab every UUID in the list as newline-separated text in one click.
A 128-bit identifier that's almost entirely random, following the RFC 4122 format, with a handful of fixed bits marking it as version 4. The randomness is what makes collisions practically impossible without any central coordination between systems generating IDs.
Yes. GUID (Globally Unique Identifier) is Microsoft's name for the same format UUID describes elsewhere — same structure, same 36-character hyphenated form, just different naming conventions depending on the ecosystem.
No, only version 4. It doesn't generate v1 (timestamp + MAC address based), v5 (deterministic, derived from a namespace and name), or v7 (time-ordered, increasingly used for database primary keys since it sorts naturally).
Yes, in any modern browser: UUIDs are generated with crypto.randomUUID, a cryptographically secure random source. A weaker Math.random()-based fallback exists only for very old browsers that lack crypto.randomUUID, which is effectively none in current use.
Up to 100 per click, each with its own Copy button, plus a Copy All button for the whole batch.
No. Every UUID is generated in your browser using JavaScript. Nothing is sent to or stored on a server.