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// HASHING & CRYPTO · BROWSER

UUID Generator

Generate up to 100 random version 4 UUIDs at once with crypto.randomUUID, in your browser.

CRYPTO · IN YOUR BROWSER

Runs in your browser; nothing you type leaves this page. Too long to share as a link.

HISTORY

Your last 5 runs appear here for 7 days, on this device only.

RESULT

Fill in the form and run the tool; the result appears here.

UUID Generator creates random version 4 universally unique identifiers (RFC 4122) with the browser's native crypto.randomUUID, up to 100 at a time, without sending anything to a server.

How to read the result

The output is one UUID per line in the standard lowercase, hyphenated form. The first character of the third group is always 4, the version digit; 122 of the 128 bits are random.

Defender tips

  • Use random UUIDs instead of sequential, incrementing integer IDs for anything reachable by an untrusted client; sequential IDs are exactly what makes IDOR-style enumeration attacks easy.
  • Do not treat a UUID as a secret or an access-control mechanism on its own; it prevents guessing, not authorisation, so still check that the caller is allowed to access the resource the UUID names.

FAQ

Can it make time-ordered (v7) UUIDs?

No, only version 4. A v7 UUID puts a timestamp in its leading bits so later IDs sort after earlier ones, which helps database index locality; it is usually generated by your database or language library at insert time.

How likely is a collision?

Vanishingly unlikely at any realistic scale for v4: the random portion has enough bits that collisions are not a practical concern even generating billions of IDs.

Are UUIDs safe to expose in a URL?

They are far better than sequential IDs for that purpose, since they cannot be enumerated by guessing, but the resource behind a UUID still needs its own authorisation check; an unguessable ID is not the same as an authorised one.