UUIDs generator

THE PRACTICAL GUIDE · NORMANDIN SYSTEMS

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The UUID generator produces identifiers using NIL, v1, v3, v4, v5, v6, or v7, with a quantity control for one through fifty values. Select uppercase output or remove hyphens when a receiving system requires that presentation. Versions v3 and v5 additionally require a namespace and a name because their output is derived from those inputs. Other generation modes have different relationships to randomness and time, so choose the version specified by your application rather than changing it solely for appearance. The page is useful for fixtures, examples, and compatibility checks. An identifier does not establish permission to access a record and should not be treated as an authentication secret.

Guide updated October 13, 2026

How to use this tool

1. Select the UUID version required by your application and set the quantity from one through fifty.
2. For v3 or v5, choose a namespace preset or enter an accepted namespace UUID, then enter the exact name to be mapped.
3. Select Uppercase or No hyphen only if the receiving format requires it. Review the displayed identifiers and use Refresh when you want the generator to run again.
4. Copy the output and test its import into the intended field. Name-based versions repeat the same identifier for unchanged namespace and name inputs.

SEE IT IN PRACTICE

A worked example

Version v5; namespace DNS; name example.com; quantity 1; lowercase with hyphens

cfbff0d1-9375-5685-968c-48ce8b15ae17

The DNS namespace UUID and the exact name determine this result. Repeating the same inputs produces the same identifier; changing the name or namespace changes the mapping.

Choose random, time-related, or name-based generation deliberately

Version v4 uses random generation. Versions v1, v6, and v7 incorporate time-related information in their construction, with different layouts and ordering properties. Versions v3 and v5 are deterministic namespace-and-name mappings, using different digest algorithms. These distinctions affect reproducibility and how identifiers relate to generation time. A UUID that sorts conveniently is still not a substitute for an explicit event timestamp, and a deterministic UUID is unsuitable when the intended behavior is a fresh value on each generation.

Namespace and formatting are separate choices

The v3 and v5 controls offer DNS, URL, OID, and X500 namespace presets as well as an editable namespace field. The name is interpreted within that namespace; it is not a request to contact a website or verify a domain. Uppercase and No hyphen affect how the result is displayed after generation. Preserve a consistent representation when comparing exported text, and test receiving validators because some require the conventional 8-4-4-4-12 grouping even though the underlying identifier occupies the same 128 bits.

When this tool is useful

• Create application fixture IDs
• Populate a mock dataset
• Compare supported UUID versions

Tips for a better result

• A UUID is an identifier, not an authorization decision or a guaranteed secret.
• Keep names byte-for-byte consistent in v3 and v5 workflows. Differences in case, spaces, or normalization can change the generated value.
• Use the canonical hyphenated form when testing a strict UUID parser; removing hyphens changes the text representation, not the identifier bits.

Frequently asked questions