UUID Generator
Generate UUIDs and GUIDs in bulk (v4 random, v7 time-ordered, v1 or v5 namespace) then copy or download them.
How it works
Pick a version, pick how many you need, and the UUIDs appear instantly — v4 uses
crypto.getRandomValues(), the browser's cryptographically secure random
source, so the 122 free bits are as unpredictable as any server-side generator. v7
puts a millisecond Unix timestamp in the leading bits so the identifiers sort
chronologically, v1 encodes a 100-nanosecond timestamp with a random (multicast) node
ID instead of leaking your MAC address, and v5 derives a deterministic UUID by hashing
a namespace plus a name with SHA-1 via the Web Crypto API. GUID and UUID mean the same
thing, so the braces option gives you the Microsoft-style
{00000000-0000-0000-0000-000000000000} form.
Everything is computed in your browser: no request is made to any server, nothing is
logged, and the page works offline once loaded. That matters for identifiers you intend
to use as production primary keys or API tokens — a UUID that was generated on someone
else's machine is not really yours. Generate up to 1,000 at a time, then copy them all
or download them as a plain .txt file, one per line.
Frequently asked questions
What is a UUID v4?
A UUID v4 is a 128-bit identifier written as 36 characters, where 122 of the bits come from a cryptographically secure random source. Version 4 is the default because it needs no coordination: two generators anywhere in the world will practically never produce the same value, so you can mint IDs offline without a central sequence.
How do I generate a UUID online without trusting a server?
Choose a version and a quantity on this page and the UUIDs appear instantly. They are created locally with the browser's Web Crypto API (crypto.getRandomValues for v4, v7 and v1, SHA-1 for v5), so no request is sent anywhere and nothing is logged. That makes it safe even for identifiers you will use as production primary keys or tokens.
What is the difference between UUID v4 and UUID v7?
v4 is fully random, so consecutive values scatter across a database index and cause page splits. v7 puts a 48-bit Unix millisecond timestamp in the leading bits and fills the rest with random data, so the IDs sort chronologically and append neatly to a B-tree primary key while staying unguessable. GUID is simply Microsoft's name for the same format.