Invalid UUID Version – Check the Version Nibble

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Show how a UUID can match the text layout but fail the validator's version check.

36 chars · 1 line

Needs attention

Invalid RFC 4122 UUID

UUID version bits

How can a canonical UUID have an invalid version?

The hyphens and hexadecimal groups can be perfectly formatted while the version nibble still falls outside the range VetaTool accepts. The validator reads the first hexadecimal character of the third group and accepts versions 1 through 8. This tool is free to use. No account or payment is required.

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What you can do here

  • Canonical 8-4-4-4-12 UUID validation
  • UUID version inspection
  • RFC 4122 variant checking
  • Nil UUID recognition
  • Uppercase hexadecimal support
  • Browser-local validation

Steps

  1. Confirm the UUID has canonical 8-4-4-4-12 structure.
  2. Inspect the first hexadecimal digit of the third group.
  3. Verify that the encoded version is within 1 through 8 for this validator.

Format and version are separate checks

The example uses 9 as the version nibble. It passes the hexadecimal layout matcher, but VetaTool then rejects it as an invalid RFC 4122 UUID because the version is outside the accepted 1-8 range.

Invalid version nibble example

The third group starts with 9, which the current validator rejects.

UUID input

550e8400-e29b-91d4-a716-446655440000

Validation result

Invalid RFC 4122 UUID

Common questions

Frequently asked questions

Where is the UUID version encoded?

In canonical UUID text, VetaTool reads the first hexadecimal character of the third group as the version nibble.

Which UUID versions does this validator accept?

The current validator accepts encoded versions 1 through 8.

Recommended next steps

Invalid UUID VariantCheck a UUID whose variant bits fall outside the RFC 4122 range accepted by the validator.UUID Version DetectionRead the version nibble from a canonical UUID and identify values such as UUID v1.UUID Generator & Validator OnlineGenerate UUID v4 batches or validate canonical UUID format, version, and variant locally.

Debugging a specific UUID issue? Browse UUID troubleshooting.