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UUID Generator

Generate random UUID v4 or time-ordered UUID v7 identifiers in bulk, using your browser’s secure random generator.

Runs locally, never uploaded

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Version

UUIDs

0 chars · 0 B

What it does

A UUID (universally unique identifier) is a 128-bit value written as 32 hexadecimal digits in five groups, such as 3f2b8c1e-9a4d-4e7b-8c2f-1d5e6a7b8c9d. UUIDs can be created anywhere, by any program, without asking a central server, and still be unique. That is why they are used as database keys, request IDs, file names and message identifiers.

This generator creates UUIDs in your browser using the cryptographically secure crypto.getRandomValues API. It follows RFC 9562, the current UUID standard.

How to use

  1. Choose v4 for random IDs or v7 for IDs that sort by creation time.
  2. Pick How many you need, from 1 to 1000.
  3. Turn Hyphens off for a compact 32-character form, or Uppercase on for systems that expect capital letters.
  4. Click Generate for a new batch, then copy or download the list.

Example

Five version 4 UUIDs look like this:

9b2c7f0e-5d1a-4c3e-a8f7-2e6b1d0c9a84
1f4e8a2b-7c3d-4b9e-8d1f-6a5c2e7b3f90
c0a7d3e9-2b6f-4e1a-b5c8-9d4f7a1e2c63
5e9b1c4d-8a2f-4d7e-9c3b-0f6a8e2d1b57
a3f6e2d8-1c9b-4a5e-87d4-3b2c0e9f6a18

The 4 at the start of the third group is the version, and the first digit of the fourth group (8, 9, a or b) marks the RFC variant.

Which version should I use?

  • Use v7 for new database primary keys. It keeps inserts fast and lets you sort records by creation time without an extra column.
  • Use v4 when the ID must not reveal when it was created, for example in public URLs.

FAQ

› What is the difference between UUID v4 and v7?

Version 4 is 122 bits of pure randomness. Version 7 starts with the creation time in milliseconds followed by random bits, so v7 IDs sort by creation time. That makes them much friendlier as database primary keys because new rows are appended to the end of the index.

› Can two generated UUIDs collide?

In practice, no. With 122 random bits you would need to generate about a billion UUIDs per second for 85 years to reach a 50% chance of a single duplicate.

› Is a UUID the same as a GUID?

Yes. GUID is Microsoft's name for the same 128-bit identifier. Some Microsoft tools print it in uppercase or wrapped in braces.

› Are these UUIDs safe to use as secrets?

They are generated with the browser's cryptographically secure random generator and never leave your device. Still, prefer a dedicated token format for API keys and session secrets.