UUID4 Generator

Generate random UUIDs

UUID4

Click 'Generate' to create your first UUID4

History

History is stored locally only and not sent to any server

No history yet

Generate values to see your history here

Technical Details

Version:
4 (Random)
Length:
36 characters
Format:
8-4-4-4-12 hex pattern
Entropy:
122 bits

Structure Breakdown

Time Low:32 bits (random)
Time Mid:16 bits (random)
Time High:16 bits (random + version)
Clock Sequence:16 bits (random + variant)
Node:48 bits (random)

Security and Best Practices

Highly secure for most applications
  • • Uses cryptographically secure random number generation
  • • No timestamp or MAC address leakage
  • • Completely unpredictable output
  • • Safe for security-sensitive applications

When to Use

  • Database primary keys
  • Session identifiers
  • API keys and tokens
  • File names for uploads
  • Transaction identifiers

Performance Characteristics

Generation Speed:
Very fast
Memory Usage:
Minimal
Collision Probability:
Virtually zero
Sortability:
Not sortable by creation time