Generate UUID v4 and v7 in bulk, in your browser
Create one id or a thousand, in v4 (random) or v7 (time-ordered), in whichever format your codebase expects. Every id comes from your browser's cryptographic random source (0 uploads, works offline) — so the ids you are about to put in a production database were never seen by anyone else's server.
How to use it
- Choose v4 for pure randomness or v7 if you want ids that sort by creation time.
- Set How many — anything from 1 to 1000.
- Pick a Format: standard, uppercase, braced
{…}or without dashes. - The ids appear immediately. Copy them, or Download as a text file.
- The presets cover the usual cases: a single id, a batch of 100, or dash-free keys.
FAQ
How do I generate a UUID online for free?
Pick a version and a count on this page and the ids appear instantly, generated by crypto.getRandomValues in your own browser. Nothing is uploaded and there is no sign-up. v4 gives 122 bits of randomness — collisions are not a practical concern even across billions of ids.
Should I use v4 or v7?
Use v7 for database primary keys and v4 for everything else. v7 puts a 48-bit timestamp at the front, so ids generated later sort after earlier ones — which keeps B-tree indexes compact instead of fragmenting them the way random v4 keys do. v4 is the right choice when you specifically do not want creation time to be inferable.
Are these UUIDs actually random?
Yes. They come from the browser's cryptographically secure random number generator, never from Math.random(). The version and variant bits are set exactly as RFC 4122 and RFC 9562 require, so the output is valid anywhere a UUID is expected.
Is it safe to generate production ids on a website?
On this one, yes, and the reason is checkable: the generation happens entirely in your browser, so the ids never reach us. Turn off your Wi-Fi and the page still produces ids. That is not true of tools that generate ids server-side, where every id you take has been seen by someone else's infrastructure.
Can I generate a lot at once?
Up to 1000 per run, and the page stays responsive because the work is local. For larger volumes, run it a few times or generate them in your own code — at that scale you probably want them created where they are used.
Limits
1 to 1000 ids per run. v7 encodes the timestamp from your device's clock, so ids generated on a machine with a badly wrong clock will sort wrongly. The four formats cover the common conventions; if your system needs another shape, copy the standard form and transform it.
Related
The password generator shares the same cryptographic random source, and the hash generator covers the other half of most id-and-digest workflows.
Bookmark this page (Ctrl+D, or ⌘D on Mac) or install the app — it works offline the next time you need it.