Free UUID v4 Generator

Generate RFC 4122 compliant UUID version 4 identifiers for databases, APIs, and unique references

About UUIDs
• Version 4 (Random)
• RFC 4122 compliant
• 122 bits of randomness

You might also like

View All 136 Tools

UUID v4 Generator - RFC 4122 Compliant Unique Identifier Tool

Generate RFC 4122 compliant UUID version 4 identifiers using cryptographically secure random numbers. Perfect for creating unique identifiers in databases, APIs, and distributed systems.

Features

  • RFC 4122 Compliant: Follows the official UUID v4 specification
  • Cryptographically Secure: Uses secure random number generation
  • Multiple Formats: Uppercase, lowercase, with/without hyphens
  • Bulk Generation: Create multiple UUIDs at once
  • Copy Options: Copy individual UUIDs or all at once
  • Format Validation: Verify UUID format and version

UUID v4 Format

UUID v4 follows the pattern: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx

  • The 13th character is always ‘4’ (version identifier)
  • The 17th character is always ‘8’, ‘9’, ‘A’, or ‘B’ (variant identifier)
  • All other characters are randomly generated hex digits

Common Use Cases

  • Database primary keys and foreign keys
  • API request and response identifiers
  • Session tokens and tracking IDs
  • File and document unique identifiers
  • Distributed system correlation IDs
  • Software licensing and activation keys

Technical Details

  • Version: UUID v4 (random)
  • Entropy: 122 bits of randomness
  • Collision Probability: Negligible for practical purposes
  • Format: 8-4-4-4-12 hexadecimal digits
  • Case: Supports both uppercase and lowercase output
From the same team