UUID v5 Generator

FREE ONLINE TOOL · RFC 9562

Generate deterministic, name-based UUID v5 identifiers using SHA-1. Choose a namespace and enter a name. Everything runs in your browser.

Namespace Name or value to convert

Your UUID v5 result

Click Generate to create a UUID v5

Same namespace + same exact name = same UUID v5.

Runs locally using the browser’s Web Crypto API (SHA-1), with UTF-8 name encoding as specified by RFC 9562. Requires HTTPS. Input is not sent to our server.

What is a UUID v5?

A UUID version 5 is a 128-bit identifier calculated from a namespace UUID and a name. Unlike random UUID v4, UUID v5 is deterministic: the same namespace and exact name generate the same output each time.

UUID v5 applies SHA-1 to the 16-byte namespace followed by the UTF-8 encoded name, then sets the UUID version and variant bits. This is specified in RFC 9562. SHA-1 is used here for UUID compatibility, not for storing passwords or making authentication secrets.

How to generate a UUID v5

Choose the DNS, URL, OID, X.500 or Custom namespace.
Enter the name exactly as you want it identified. Names are case-sensitive: Example.com differs from example.com.
Click Generate UUID v5, then copy the resulting UUID.

Example

Namespace: DNS
Name: www.example.com
Expected output: 2ed6657d-e927-568b-95e1-2665a8aea6a2

UUID v5 vs UUID v4

UUID v5: reproducible for a given namespace and name; useful for stable names and mapping external identifiers. UUID v4: generated with random bits; better for new unrelated identifiers that must not reveal deterministic name relationships. UUID v5 hashes are not reversible in general, but guessable names can be tested against known namespaces.

Common use cases

Use UUID v5 for consistent identifiers derived from domain names, URLs, database keys, or names in a fixed namespace. Avoid it for session secrets, authentication tokens, password storage, or situations requiring a fresh unpredictable ID each time.

Frequently asked questions

Will the same name always produce the same UUID v5?

Yes, provided both the namespace UUID and exact name bytes are identical.

What is the difference between UUID v3 and v5?

Both are deterministic name-based UUIDs. UUID v3 uses MD5; UUID v5 uses SHA-1.

Can I use a custom namespace?

Yes. Select Custom namespace UUID and enter a 128-bit UUID in canonical 8-4-4-4-12 format.

Does UUID v5 contain a timestamp?

No. UUID v5 does not encode a creation timestamp.

Does this tool send my name to a server?

No. The generation algorithm executes inside your browser. Standard website resources may still load as usual.