UUID Generator

Generate Universally Unique Identifiers (UUID) version 4. Perfect for databases, APIs, and unique record identifiers.

Max: 100 UUIDs

Generated UUIDs (1)

#1c239b041-20a3-4852-8658-24ada3209b2d

About UUID v4

These are randomly generated UUIDs (version 4). The chance of generating a duplicate is astronomically small (1 in 2^122). All UUIDs are generated locally in your browser using cryptographically secure random numbers.

UUID Format Examples

Standard (with hyphens, lowercase):

550e8400-e29b-41d4-a716-446655440000

Uppercase with hyphens:

550E8400-E29B-41D4-A716-446655440000

Without hyphens (compact):

550e8400e29b41d4a716446655440000

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit number used to identify information in computer systems. The term GUID (Globally Unique Identifier) is also used, particularly in Microsoft systems.

UUID Format

A UUID is typically represented as 32 hexadecimal digits, displayed in five groups separated by hyphens:

xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx

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

Common Use Cases

  • Database Keys: Primary keys in distributed databases
  • API Identifiers: Unique request or transaction IDs
  • File Names: Unique file or object identifiers
  • Session IDs: Web session tracking
  • Distributed Systems: ID generation without coordination

UUID v4 Specifications

  • Generated using random or pseudo-random numbers
  • 122 bits of randomness (2^122 possible UUIDs)
  • Collision probability is extremely low
  • No central registration authority needed
  • Can be generated offline

Why Use UUIDs?

  • Globally unique without coordination
  • Can be generated anywhere, anytime
  • No database lookup required for uniqueness
  • Ideal for distributed systems
  • Prevent enumeration attacks (unlike sequential IDs)