UUID Generator

About this UUID generator

A UUID (Universally Unique Identifier) is a 128-bit value used to identify things without a central authority — database rows, API resources, files, and events. This generator produces random v4 UUIDs and time-ordered v7 UUIDs, plus the special Nil UUID, in bulk and ready to copy.

Generation is cryptographically secure and happens entirely in your browser. Generate one or up to 256 at a time, then copy individually or all at once.

Which version should I use?

• v4 — random and unguessable. The safe default for public IDs and tokens.
• v7 — time-ordered. Best for database keys because new IDs sort to the end, keeping indexes efficient.
• Nil — the all-zero placeholder value.

Frequently asked questions

What is the difference between UUID v4 and v7?

v4 is fully random, which is great for unguessable identifiers. v7 embeds a millisecond timestamp at the front, so v7 UUIDs sort in roughly the order they were created — ideal as database primary keys because they keep indexes compact.

Are these UUIDs safe to use as unique IDs?

Yes. They are generated with the browser's cryptographically secure random number generator (crypto.getRandomValues), so collisions are astronomically unlikely.

Are the UUIDs generated on a server?

No. Every UUID is generated locally in your browser. Nothing is sent anywhere, so you can use them freely in private projects.

What is the Nil UUID?

The Nil UUID is the special all-zero value (00000000-0000-0000-0000-000000000000). It is often used as a placeholder or default that clearly means “no UUID”.

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