Randomly

UUID Generator

Random v4 or time-ordered v7 UUIDs, 1 to 50 at a time, generated in your browser and ready to copy.

Output · 0 UUIDs · v4

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No items.

Each UUID v4 is 122 bits of `crypto.getRandomValues` entropy with the version (0100) and variant (10) bits set per RFC 9562. Collision risk is negligible for any realistic use.

0 · v4
Bits of entropy
122
Versions
v4 · v7

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Guides

This UUID generator makes version 4 or version 7 UUIDs, from 1 to 50 per batch. They come out in the standard lowercase 8-4-4-4-12 format, ready to paste into a database seed, a test fixture or an API request.

Version 4 is plain random: 122 random bits from your browser's crypto.getRandomValues, with the version and variant bits set as RFC 9562 says. Version 7 starts with a 48-bit millisecond timestamp and fills the rest with random bits, so IDs created later sort after earlier ones. That's useful for database primary keys.

Everything is generated in your browser. The tool remembers the count and version you picked last time.

v4 or v7: which UUID should you pick?

Pick v4 when you only need an ID nobody can guess and order doesn't matter. Pick v7 when the IDs become primary keys in an indexed table. Because v7 values increase over time, new rows land at the end of the index and don't get scattered through it. The catch is that a v7 UUID reveals roughly when it was created.

How to use the UUID generator

  1. Choose v4 (random) or v7 (time-ordered).
  2. Set the Count slider anywhere from 1 to 50.
  3. Press Generate or Regenerate for a fresh batch.
  4. Click one UUID to copy it, or press Copy all to get the batch one per line.

Example UUID outputs

Two v4 UUIDs and one v7. In a v4 the first digit of the third group is always 4, and in a v7 it's always 7:

  • 9f8c1a22-6b4f-4e8f-a2e7-3d7a18b6e921 (v4)
  • c1d9f50f-8682-4cfa-9a5e-8f3b21d4a7c2 (v4)
  • 01a102c1-2083-7c26-943c-d55ddbb51efb (v7)

Frequently asked questions

What does UUID stand for?

Universally unique identifier. It's a 128-bit value, usually written as 32 hex digits in five groups separated by hyphens.

Is this UUID generator free?

Yes, with no sign-up and no limit beyond 50 per batch.

Can two generated UUIDs ever collide?

In theory, yes. In practice, no. A v4 has 122 random bits, so you'd need to generate around 2.7 quintillion of them for a 50% chance of a single duplicate.

Are these UUIDs safe to use as secrets?

The v4 randomness comes from a cryptographic source, but a UUID is meant to identify things, not authenticate them. For API keys or reset tokens, use a dedicated token generator. Never use v7 as a secret, since part of it is a timestamp.

What's the difference between a UUID and a GUID?

Same thing, different name. Microsoft calls them GUIDs and often writes them in uppercase with braces. The GUID generator linked on this page outputs that style.

Built and maintained by Bipul Kumar. Found a wrong number or a broken result? Tell me and I'll fix it.