It looks like your browser language isn't English. Would you like to switch to the Traditional Chinese version? 切換到繁體中文 ×

UUID / GUID Generator

security Security & Privacy Guarantee

Built for developers, this tool runs 100% locally in your browser, using the Web Crypto API's cryptographically secure random number generator. Nothing is sent to a server.

v7 embeds a millisecond timestamp so generated IDs sort roughly by creation time — a good fit for database primary keys.

Result

Waiting for input...

FAQ

Q: What's the difference between UUID v4 and v7?

A: UUID v4 is fully random — great for general-purpose unique IDs, but random ordering hurts database index performance when used as a primary key. UUID v7 embeds a 48-bit millisecond timestamp in the first part of the value, so newly generated UUIDs sort roughly in creation order, which is friendlier to B-tree indexes while still being globally unique.

Q: Is it safe to use these UUIDs as secret tokens (e.g. password reset links)?

A: v4 UUIDs are generated from a cryptographically secure random source (Web Crypto), so the random part is safe to use as an unguessable identifier. v7 UUIDs are not — part of the value is a predictable timestamp, so avoid v7 for anything that must not be guessable.

Done