UUID v5 Generator

Generate deterministic RFC 9562 version 5 UUIDs by hashing a namespace UUID and UTF-8 name with SHA-1.

Description

Create the RFC UUID namespace and SHA-1 form and display its canonical lowercase identifier.

UUID v5 hashes the 16 namespace bytes followed by the UTF-8 name with SHA-1, then sets the version and variant bits. It is deterministic and normally preferred over v3 when compatibility permits. UUID text contains 32 hexadecimal digits grouped with hyphens, but the version and variant bits assign meaning to parts of the 128-bit value.^[1]

When to use UUID v5 Generator

Use UUID v5 Generator only when its identity, ordering, privacy, or compatibility properties match the receiving system. Choosing a UUID version is part of the data model, not merely a formatting preference.

How UUID v5 Generator works

UUID v5 hashes the 16 namespace bytes followed by the UTF-8 name with SHA-1, then sets the version and variant bits. It is deterministic and normally preferred over v3 when compatibility permits.^[1]

How the UUID v5 function processes input

Encode the entered text as UTF-8 bytes.
Process the bytes with the selected algorithm and its exact parameters.
Render the result in the canonical textual form shown by the tool.

Limitations and assumptions

UUID uniqueness depends on following the version's generation rules and on the quality of its time, namespace, node, or random inputs.
Time- and node-based forms can disclose metadata; use randomized node values when hardware identity should remain private.
UUIDs are identifiers, not secrets, passwords, signatures, or proof that an object exists.

Alternative or Complementary approaches

Use UUID v4 for opaque random identifiers, UUID v5 for reproducible namespace/name identifiers, or UUID v7 for time-ordered database keys.

References

RFC 9562: Universally Unique IDentifiers (UUIDs) — Internet Engineering Task Force

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UUID Parser
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