UUID Generator

Free · no signup · runs entirely in your browser

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Need a few unique identifiers right now, without installing anything or writing a throwaway script? That is the whole job here. Press a button, get UUIDs, copy them, move on with your day.

A UUID is a 128-bit identifier written as 36 characters: five groups of hexadecimal digits separated by hyphens, like 3f2b8c1e-9a4d-4e7b-8c21-5d6f0a1b2c3d. The point of a UUID is that you can make one anywhere, with no central counter, and it will almost certainly never match anyone else's. Developers use them as database keys, file names, request IDs, test fixtures and placeholders.

This generator makes version 4 UUIDs, the random kind. Set how many you want in the count box, press Generate, and the list appears in a text area, one per line. The count starts at 5. The box is marked as accepting 1 to 100, and that is the range to stick to. Press Copy All and the entire list goes to your clipboard, ready to paste into a spreadsheet, a SQL insert or a JSON file.

The output is lowercase with hyphens. There are no formatting options, so if you need uppercase or the hyphens stripped, you will do that in your editor afterwards. There is also no per-line copy button, just the one that copies the whole list.

One technical note. Each UUID comes from your browser's cryptographic random source (crypto.randomUUID, with crypto.getRandomValues as the fallback in older browsers), not from Math.random. So the values are unguessable as well as unique.

Everything runs in your browser. The UUIDs are produced on your machine by JavaScript on this page. There is nothing to sign up for and no fee.

How to use it

  1. Type how many UUIDs you want into the count box (it starts at 5; anything outside 1 to 100 is clamped to that range).
  2. Press Generate UUIDs. The list appears in the text area, one UUID per line.
  3. Press Copy All to put the whole list on your clipboard, then paste it where you need it.

Worked example

You are seeding a test database with ten users and need ten primary keys. Set the count to 10 and press Generate UUIDs. Ten lines appear, each in the form xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, where the 4 marks version 4. Press Copy All, paste into your seed file, and add a name next to each line. Need ten more later? Press Generate again; you get a fresh list.

FAQ

Which UUID version does this generate?

Version 4, the random kind. You can see the 4 in the third group of every result. Nothing else is generated.

Is it safe to use these UUIDs as security tokens?

They come from the browser's cryptographic random generator, so they are unguessable in practice. A UUID v4 carries 122 random bits. For a real session token, many systems still prefer a longer random string, but these are not built from Math.random.

How many UUIDs can I make at once?

Between 1 and 100 per press. The box starts at 5, and a number outside that range is clamped to 1 or 100.

Does anything leave my browser?

No. The UUIDs are generated by JavaScript on the page in your browser, with no signup. The Copy All button writes to your own clipboard.

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