The Nil UUID Explained
The Nil UUID is 00000000-0000-0000-0000-000000000000. See when to use it, how validators treat it, and why it is not a random ID.
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The Nil UUID Explained
RFC 9562 defines a Nil UUID of all zero bits. It is a valid UUID used as a sentinel — “no value yet” — not as a unique identifier. Do not generate it when you need uniqueness.
Worked example: The all-zero Nil UUID
UUID
00000000-0000-0000-0000-000000000000
Validator result
✓ Valid UUID Type: Nil UUID (all zero bits, RFC 9562)
Practical tip
In APIs, prefer null or omitting the field over sending the Nil UUID, unless a spec (such as some COM interfaces) requires it.
How to use this UUID Generator
- 1Use the live tool above — it runs entirely in your browser and never uploads your data.
- 2Paste the sample from the worked example, or use your own input.
- 3Copy the result, then adapt the same steps in your editor, script, or pipeline.
The Nil UUID Explained FAQs
Is the Nil UUID valid?
Yes. Validators should accept it and label it as Nil, not as version 0 in the usual sense.
What is the Max UUID?
RFC 9562 also defines a Max UUID of all one bits (ffffffff-ffff-ffff-ffff-ffffffffffff) as the other sentinel.
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