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UUID v4 Generator

Generate random UUID v4 strings.

✓ Free ✓ No Sign-up ⚡ Instant Developer Tools

UUID v4 Generator

Generate random UUID v4 strings instantly.

How many UUIDs?

What is UUID v4 Generator?

UUID v4 Generator produces a unique identifier string 36 characters long.

How Does It Work?

The tool uses the Web Crypto API (crypto.getRandomValues()) to generate 16 random bytes according to RFC 4122.

Common Use Cases

  • Database primary keys - A unique ID that's safe to share publicly.
  • Session & token IDs - A session identifier that can't be guessed.
  • Distributed systems - Generate unique IDs across many servers.
  • File naming - Avoid file name collisions on upload.
  • Testing & mocking - Dummy data with valid UUIDs.

Frequently Asked Questions

Q: Is a UUID v4 truly unique?

A: Yes, the chance of a collision is 1 in 2.7 quintillion.

Q: What's the difference between UUID v1 and v4?

A: UUID v1 uses a timestamp and MAC address. UUID v4 is fully random.

Q: Can it be used as an API key?

A: It can, but a UUID has no checksum or signature for authentication.