UUID Generator

Generate various types of UUIDs (Universally Unique Identifiers) for your applications. Choose from different versions based on your specific needs.

v1MAC + Timestampv4Randomv6Timestamp Reorderedv7DB OptimizedNILEmptyGUIDMicrosoft

NIL UUID (Empty)

Generate the special nil UUID consisting of all zeros. Used as a null or empty value in systems that require a UUID format but need to represent the absence of a real identifier.

Bulk Generation

Generate multiple UUIDs at once for batch operations

Or

Only 1 to 10,000 allowed

API Information

Use these endpoints to integrate UUID generation into your applications

GEThttps://fastweb.tools/api/uuid/nil

Generate a single nil UUID

GEThttps://fastweb.tools/api/uuid/nil?count=100

Generate multiple nil UUIDs (max: 10,000)

What is NIL UUID? Empty

The NIL UUID (also called NULL UUID) is a special UUID consisting entirely of zeros. It represents an empty or uninitialized UUID value and is standardized in RFC 4122.

Standard Format:

00000000-0000-0000-0000-000000000000

Properties:

  • Always the same value (all zeros)
  • Universally recognized as empty/null
  • No randomness or timestamp information
  • Version and variant bits are also zero

When to Use NIL UUID

✅ Perfect For:

  • Default/placeholder values in databases
  • Representing uninitialized or null references
  • Validation and testing scenarios
  • Indicating missing or invalid UUIDs
  • Configuration files with optional UUID fields

❌ Never Use For:

  • Actual unique identification (defeats the purpose)
  • Security tokens or session IDs
  • Primary keys in production databases
  • Any scenario requiring actual uniqueness

Technical Details & Use Cases

Database Usage

Commonly used as a default value for UUID columns that allow null values, or to represent unassigned foreign key references.

Programming

Used to initialize UUID variables before assignment, or to represent invalid/missing UUID values in conditional logic.

API Responses

Indicates missing or unavailable UUID values in API responses, maintaining consistent UUID format while signaling absence of data.

Programming Examples

JavaScript:const emptyId = '00000000-0000-0000-0000-000000000000';
C#:Guid.Empty