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UUID generator (v4 and v7)

Create cryptographically secure universally unique identifiers in bulk. Choose UUID v4 (fully random) or UUID v7 (time-ordered, ideal for database keys) and validate any UUID with the inspector.

Processed 100% in your browser

Output

Ctrl + Enter runCtrl + C copy result

How to use

  1. 1Pick the version: random v4 or time-ordered v7.
  2. 2Set how many UUIDs you need (up to 1000) and the format: uppercase, hyphens or braces.
  3. 3Click “Generate” or press Ctrl/Cmd + Enter.
  4. 4Copy the list or download it as TXT or JSON. Paste a UUID into the inspector to see its version and date.

Use cases

  • Primary keys in databases (v7 keeps indexes ordered).
  • Request, transaction or event IDs in distributed systems.
  • Test data and fixtures for automated tests.
  • GUIDs for .NET, Windows or COM registrations (braces format).

Frequently asked questions

What is a UUID?

A 128-bit identifier (also called a GUID) that uniquely identifies information without a central registry. It is written as 32 hexadecimal digits in 5 groups.

What is the difference between UUID v4 and UUID v7?

v4 uses 122 random bits. v7, defined in RFC 9562, starts with the Unix timestamp in milliseconds, so UUIDs created later sort later — which improves B-tree index performance in databases.

Can two UUIDs ever be the same?

In practice, no. With v4 you would need to generate about 2.7 quintillion IDs to have a 50% chance of a single collision.

Is it safe to generate them in the browser?

Yes. It uses the Web Crypto API (crypto.randomUUID and crypto.getRandomValues), a cryptographically secure generator. Nothing is sent to any server.

Does a UUID v7 reveal anything?

It reveals the moment it was created (to the millisecond). If that time is sensitive, use v4.

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