UUID Generator

How to use the UUID Generator?

Generating UUIDs on fasttools.dev is simple and fast:

  1. Select the number of UUIDs (1 to 10,000).
  2. Optionally enable Force Uppercase.
  3. Choose the output format: one per line, CSV, or JSON.
  4. Click Generate.
  5. Copy or download the result.

Generated UUIDs can be used in development, testing, databases, and APIs that require unique identifiers.

Frequently Asked Questions

What is a UUID?

UUID: Universally Unique Identifier

A UUID is a 36-character string (32 hexadecimal characters and 4 hyphens) used to uniquely identify information.

Example: 550e8400-e29b-41d4-a716-446655440000

How does the generation algorithm work?

UUID v4 Algorithm

UUIDs follow the RFC 4122 standard. Version 4 is randomly generated, reserving specific bits for version and variant.

  • 122 effective bits of entropy
  • Extremely low collision probability
  • Generated using crypto.randomUUID() in modern browsers
UUID vs GUID — What's the difference?

UUID and GUID are effectively the same concept.

  • UUID: standard defined by RFC 4122.
  • GUID: Microsoft's term (.NET, SQL Server).
Different UUID Versions

UUID versions serve different purposes:

  • v1: time-based + MAC address.
  • v3: deterministic (MD5 hash).
  • v4: fully random (default here).
  • v5: deterministic (SHA-1 hash).

⚠ Disclaimer

This tool generates UUIDs exclusively for development, testing, or educational purposes. Although it follows the RFC 4122 standard, usage in critical systems is the user's responsibility.