UUID v5 Generator

Generate deterministic UUID v5 values

UUID version 5 derives a repeatable identifier from a namespace UUID and name using SHA-1. Identical namespace and name bytes produce the same UUID, which is useful for stable IDs generated independently by multiple systems.

The available standard namespaces represent DNS names, URLs, object identifiers, and X.500 distinguished names.

How to generate UUID v5

1. Choose the namespace required by your data model or protocol.
2. Enter the exact name, including capitalization and punctuation.
3. Keep hyphens for the conventional UUID representation unless a compact format is required.
4. Generate and compare the result using the same namespace and normalization rules everywhere.

For the DNS namespace, example.com produces cfbff0d1-9375-5685-968c-48ce8b15ae17.

UUID v5 compatibility

RFC 9562 specifies UUIDv5 and its standard namespaces. SHA-1 is used here to produce a standardized name-based mapping; UUIDv5 should not be confused with a digital signature, password hash, or proof of authenticity.

Names that are logically similar but serialized differently produce different results. Agree on URL form, DNS capitalization rules, Unicode normalization, and character encoding before generating persistent identifiers.

UUID v5 FAQ

How is UUID v5 different from UUID v3?

Both are name-based and deterministic. UUID v3 uses MD5, while UUIDv5 uses SHA-1; their outputs are not interchangeable.

Does UUID v5 expose the original name?

It does not store the name directly, but predictable candidate names can be tested. Do not rely on the UUID to keep its source secret.

Can I generate a batch of UUID v5 values automatically?

This page generates one name-based value at a time because each result depends on its input name. Use a random or time-based generator when you need an unrelated batch.