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UUID Generator

Generate GUIDs for Windows and .NET

GUID (globally unique identifier) is the name Microsoft uses for the UUID standard. A GUID from .NET or Windows and a UUID from this generator are the same kind of 128-bit value with the same 8-4-4-4-12 hexadecimal layout.

Worked example

Canonical (RFC 9562, .NET "D")
3f2c8e71-9b04-4d5a-a613-e72f90c458b1
.NET "B" format
{3f2c8e71-9b04-4d5a-a613-e72f90c458b1}
Windows registry / COM
{3F2C8E71-9B04-4D5A-A613-E72F90C458B1}

How it works

  • .NET Guid.NewGuid() and Windows CoCreateGuid() produce random version 4 values, so a v4 UUID from this page works anywhere a GUID is expected.
  • Hexadecimal digits are case-insensitive: lowercase, uppercase, and braced text are different spellings of the same value. This generator outputs canonical lowercase, which Guid.Parse accepts with or without braces.
  • Windows NT 4 and earlier created time-based GUIDs equivalent to UUID v1. The v1 option here produces the same layout with a random node ID instead of a network card address.
UUID Version

Generate 1-100 UUIDs at once

About UUIDs

UUID v1: Time-based UUIDs that include a timestamp and the MAC address of the computer generating the UUID. Useful when you need to know when the UUID was created.

UUID v4: Randomly generated UUIDs. This is the most commonly used version and provides good uniqueness with minimal information leakage.

UUID v5: Name-based UUIDs using SHA-1 hashing. Given the same namespace and name, you'll always get the same UUID. Useful for deterministic UUID generation.

More UUID guides