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Nil UUID

All 128 bits set to zero. A "no value" placeholder.

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/nil

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

About the Nil UUID

The Nil UUID is the special value 00000000-0000-0000-0000-000000000000 with every bit set to zero (RFC 9562 section 5.9). It means "no UUID" and is the UUID equivalent of null.

In .NET it is Guid.Empty; in Python uuid.UUID(int=0); in PHP Ramsey\Uuid\Uuid::NIL.

When to use it

  • A placeholder or default value where a UUID column must not be NULL.

Frequently asked questions

Is the nil UUID valid?

Yes. It is explicitly defined by RFC 9562, though it has no version or variant.