UUID Generator
Generate UUID v4 or time-ordered v7 in bulk, with uppercase, braces and no-hyphen formats. Plus a UUID inspector that decodes version and timestamp.
Format and versions follow RFC 9562 (May 2024), which obsoletes RFC 4122.
We don’t have an API because we don’t have a server; a UUID from someone else’s server isn’t really yours.
UUID inspector
Paste a UUID to see its version, variant and timestamp.
How to use
- Pick a version tab: v4 (random), v7 (time-ordered), Nil or Max.
- Set ‘How many’, or press the 1, 10, 100 and 1000 buttons — up to 1,000 at a time.
- Tick the Format options — Uppercase, Hyphens, Braces, Quotes, Trailing commas — for your code.
- Paste any UUID into the inspector to read its version, variant and embedded timestamp.
- Press ‘Copy all’, ‘Download .txt’ or ‘Download .csv’; R or ‘Regenerate’ makes a fresh batch.
FAQ
Should I use UUID v4 or v7?
Use v7 for database primary keys: it starts with a millisecond timestamp, so new rows sort to the end of the index instead of scattering through it like v4 does. Use v4 for public identifiers, where an embedded creation time would leak information you did not mean to publish.
Can I tell when a UUID was created?
Only for versions 1, 6 and 7. Paste it into the inspector and we decode the embedded timestamp. Version 4 is pure randomness with no time inside — that is the point of it.
Are these UUIDs random enough to be secure?
Yes. They come from crypto.getRandomValues, the browser’s cryptographic random number generator, and they are generated in this tab. We have no API and no server, so no one else — including us — ever sees a value you generate here.
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