UUID Generator
Create RFC 4122 / RFC 9562 UUIDs. Version 4 is random; v1 and v6 are time-based; v7 is Unix-time ordered; v3 and v5 are name-based.
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How to generate UUIDs
- Choose a version. Use 4 for a random ID, 7 when you want time-sortable IDs, 3 or 5 when the same name must always map to the same ID.
- For v3 or v5, pick a namespace and enter the name exactly as the receiving system defines it.
- Set count, upper case, and hyphens if needed, then Generate.
- Copy the list. UUIDs are identifiers, not secrets.
UUID
Universally unique identifier (RFC 4122 / RFC 9562)
| Versions | 1, 3, 4, 5, 6, 7 |
|---|---|
| v3 / v5 namespaces | DNS, URL, OID, X.500, or a custom UUID |
| Random source | crypto.getRandomValues for v4 and v7. Not Math.random. |
What a UUID is
A UUID is a 128-bit identifier, usually written in 8-4-4-4-12 hex form. Version 4 bits are random. Versions 1 and 6 encode a timestamp plus a node; version 7 encodes Unix milliseconds. Versions 3 and 5 hash a namespace UUID together with a name (MD5 or SHA-1) so the same pair always yields the same ID.
Need a secret instead? Use the password generator. More generators live under Generators.
Name-based UUIDs (v3 and v5)
RFC namespaces: DNS 6ba7b810-9dad-11d1-80b4-00c04fd430c8, URL 6ba7b811-9dad-11d1-80b4-00c04fd430c8, OID 6ba7b812-9dad-11d1-80b4-00c04fd430c8, X.500 6ba7b814-9dad-11d1-80b4-00c04fd430c8. The name is taken as UTF-8 bytes. Capitalization, trailing dots, or Unicode normalization will change the result. DNS plus example.com as UUID v3 is 9073926b-929f-31c2-abc9-fad77ae3e8eb.
Time-based UUIDs (v1, v6, and v7)
Version 1 encodes a timestamp and a node. Version 6 reorders that layout so IDs sort by time. Version 7 uses Unix milliseconds and is the usual choice for new time-sortable IDs. A UUID is an identifier, not a secret. A GUID is the same 128-bit idea under a different name.