UUIDTools.com

Online GUID Generator

Random. 122 random bits. The default choice for most apps.

Decode
Options & format

Formatting is applied instantly in your browser. A GUID is a UUID: tick Uppercase + Braces for the Microsoft registry style.

API
http://uuidtools.com/api/generate/v4

Plain-text and JSON API docs: no key required.

About Version 4 UUIDs

GUID (Globally Unique Identifier) is Microsoft's name for a UUID. They are the same 128-bit value. Windows, COM, .NET and SQL Server typically show GUIDs in uppercase and often wrap them in braces, for example {6F9619FF-8B86-D011-B42D-00C04FC964FF}.

The generator below is preset for that style. Switch the options to get lowercase, no hyphens, quotes, or comma-separated output for pasting straight into code or SQL.

When to use it

  • C#: Guid.NewGuid(). SQL Server: NEWID() (random) or NEWSEQUENTIALID() (ordered). PowerShell: [guid]::NewGuid().

Frequently asked questions

What is the difference between a GUID and a UUID?

Nothing in practice. GUID is the Microsoft term, UUID the standards term. One caveat: .NET's Guid.ToByteArray() stores the first three fields little-endian, so the raw bytes differ from the RFC byte order even though the text form is identical. The decoder shows both.

Does a GUID have braces?

The braces are only a text convention (registry format). They are not part of the value.