UUID v5 Validation – Check Version 5 UUID Online

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Validate the encoded UUID version using the same canonical UUID inspector as the main UUID tool.

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Valid UUID v5

UUID version validation

UUID v5 Validation: what does the validator actually check?

UUID v5 is a name-based UUID version. VetaTool identifies a version 5 nibble in canonical UUID text but does not reproduce the SHA-1 namespace/name calculation that may have generated it. 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. Paste the UUID and confirm the first hexadecimal digit of the third group is 5.
  2. For a provenance check, convert the expected namespace ID and name to canonical octets, concatenate them in network byte order, and compute SHA-1.
  3. Keep the leftmost 128 bits of the 160-bit SHA-1 result, discard the remaining 32 bits, then replace the version field with 5 and the RFC variant bits with 10.
  4. Format and compare the recomputed UUIDv5 with the received value; VetaTool's inspector does not perform the SHA-1 derivation or truncation step.

UUID v5 uses version nibble 5

A 5 in the first hexadecimal position of the third group identifies UUID v5 when the variant bits are also accepted.

UUIDv5 starts from a 160-bit SHA-1 result, keeps only its leftmost 128 bits, and then overwrites the version and variant fields; the original namespace and name still cannot be recovered from the UUID text.

Version detection is not full semantic validation

VetaTool reads the UUID version nibble and RFC-compatible variant range. It does not reconstruct how the identifier was generated or validate every version-specific timestamp, namespace, hash, random, or custom field.

Treat the result as structural UUID inspection. Protocols and applications can impose additional requirements beyond the encoded version number.

UUID v5 Validation example

RFC 9562 UUIDv5 test vector for the DNS namespace and www.example.com. UUIDv5 keeps the leftmost 128 SHA-1 bits, discards 32 bits, then sets the version 5 and RFC variant fields.

UUID input

2ed6657d-e927-568b-95e1-2665a8aea6a2

Validation result

Valid UUID v5

Common questions

Frequently asked questions

Why is UUID v5 128 bits when SHA-1 produces 160 bits?

RFC 9562 uses the leftmost 128 bits of the SHA-1 result for UUIDv5 and discards the remaining 32 bits before the version and variant fields are applied.

Does this prove the UUID was generated by a version 5 algorithm?

No. The validator confirms canonical text, the encoded version nibble, and RFC-compatible variant bits. It does not verify generator provenance or all version-specific field semantics.

Recommended next steps

UUID v3 ValidationCheck canonical UUID text whose version nibble identifies name-based UUID v3.SHA-1 vs SHA-256 HashCompare plain SHA-1 and SHA-256 digests while confirming that name-based UUID v5 uses SHA-1 rather than a SHA-2 digest.UUID Version DetectionRead the version nibble from a canonical UUID and identify values such as UUID v1.

Debugging a specific UUID issue? Browse UUID troubleshooting.