UUID Variant B – Check Upper RFC-Compatible Variant Boundary

Local only

Demonstrate the upper accepted boundary of the current UUID validator's variant nibble check.

36 chars · 1 line

Waiting for input

Valid UUID v4

UUID variant inspection

Is hexadecimal B valid in the UUID variant position?

VetaTool converts the first digit of the fourth UUID group from hexadecimal and accepts values 8 through 11. Hexadecimal B equals decimal 11, so it is the upper accepted boundary in the current variant check. This tool is free to use. No account or payment is required.

Last updated

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 format and version nibble are otherwise valid.
  2. Read B as hexadecimal 11 in the first digit of the fourth group.
  3. Compare it with an invalid variant such as 7 or C to understand the validator boundary.

B is accepted; values above B are not

The current inspector's explicit numeric check accepts variant values from 8 through 11 inclusive. B is 11 in hexadecimal, so it passes.

A value such as C converts to 12 and fails with Invalid RFC 4122 UUID even when the rest of the UUID is canonical.

Variant nibble B example

The fourth group begins with hexadecimal B and the UUID remains version 4.

UUID input

550e8400-e29b-41d4-b716-446655440000

Validation result

Valid UUID v4

Common questions

Frequently asked questions

Is C also accepted as a variant nibble?

No. The current inspector accepts only hexadecimal 8, 9, A, and B for its RFC-compatible variant range.

Does variant B make this UUID version B?

No. The version remains 4 because version and variant are encoded in different UUID positions.

Recommended next steps

UUID RFC Variant AInspect a canonical UUID whose fourth group starts with hexadecimal A.Invalid UUID VariantCheck a UUID whose variant bits fall outside the RFC 4122 range accepted by the validator.UUID Generator & Validator OnlineGenerate UUID v4 batches or validate canonical UUID format, version, and variant locally.

Debugging a specific UUID issue? Browse UUID troubleshooting.