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UUID v5 Generator (Name-Based)

Turn names, URLs or domains into stable UUIDs: the same namespace and name always produce the same result.

Processed locally in your browser

Options

Used when the namespace is “Custom”.

The same namespace and name always produce the same UUID. Blank lines are skipped.0 chars · 0 lines
The result will appear here.

What is UUID v5 Generator (Name-Based)?

A version 5 UUID is computed by hashing a namespace UUID followed by a name with SHA-1 and formatting 128 of the resulting bits as a UUID. Version 3 does the same with MD5. There is no randomness, so the output is fully reproducible on any machine and in any language that follows RFC 9562.

Paste one name per line, choose a namespace (DNS, URL, OID, X.500 or your own UUID) and you get one UUID per line, plus a name-to-UUID table. For example, the DNS namespace with the name python.org gives 886313e1-3b8a-5372-9b90-0c9aee199e5d.

How does it work?

  1. Type or paste your names, one per line. Blank lines are skipped and surrounding spaces are trimmed by default.
  2. Pick the namespace: DNS for domain names, URL for addresses, or a custom UUID that you own.
  3. Choose v5 (SHA-1, recommended) or v3 (MD5, legacy) and the output layout.
  4. Copy the UUIDs, or download a CSV that pairs each name with its UUID.

Common use cases

  • Deriving a stable ID for a record from its natural key, such as an e-mail or a URL.
  • Reproducing the UUIDs your Python, Java or Go code creates with uuid5 to debug a mismatch.
  • Making idempotent imports: re-running the import gives the same IDs instead of duplicates.
  • Creating one namespace per application and deriving all entity IDs from it.

Examples

Try this input in the tool above:

Input
python.org
example.com
Output
886313e1-3b8a-5372-9b90-0c9aee199e5d
cfbff0d1-9375-5685-968c-48ce8b15ae17

Privacy

UUID v5 Generator (Name-Based) runs entirely in your browser. The text or files you provide are processed on your device and are not uploaded, logged or stored on our servers.

Limitations

Name-based UUIDs are not secret: anyone who guesses the namespace and name can recompute the value. SHA-1 and MD5 are only used for mixing here, not for security.

Frequently asked questions

What is the difference between v3 and v5?

They are identical except for the hash: v3 uses MD5 and v5 uses SHA-1. Prefer v5 for new work; use v3 only to match existing data.

Which namespace should I use?

Use the DNS namespace for domain-like names and URL for full URLs. For your own data, generate one random UUID once, keep it as your application namespace, and use it as a custom namespace.

Why is my UUID different from another tool’s?

Check the namespace, the exact name (case, spaces and line endings matter) and the version. Even a trailing space changes the result; this tool trims spaces by default, and you can turn that off.

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