Don's Tools · Developers · UUID Generator

UUID generator

Generate secure v4 and time-ordered v7 UUIDs in bulk, right in your browser. Nothing is uploaded.

Version
How many
Good to know: v4 is fully random; v7 is time-ordered and sorts by creation time.
UUID Generator is a free developer tool that creates universally unique identifiers entirely in your browser using a cryptographically secure random source, with nothing uploaded. It produces random version 4 UUIDs, time-ordered version 7 UUIDs and the Nil UUID, in bulk up to 1000 at a time, with options for uppercase, no hyphens or surrounding braces.

Files are processed in your browser and never uploaded.

How to use UUID generator

  1. Set the options

    Choose How many, Uppercase, Wrap in braces and No hyphens. Nothing is hidden until you press a button.

  2. Press Generate, Don →

    The result is produced on your own device, using your browser's own random and crypto functions where randomness is involved.

  3. Keep the result

    Copy copies it and Download .txt saves it as a file.

What this tool does

Random v4 and time-ordered v7

v4 is random, which is what most systems want. v7 is time-ordered, so a set of them sorts by creation and indexes far better in a database.

Generate up to 1000 at once

Generate up to 1000 at once, which is enough to seed a table or a fixture file in one go.

Uppercase, no-hyphen and brace options

Uppercase, no hyphens and brace-wrapped forms are all available, because different platforms insist on different shapes.

Cryptographically secure source

Values come from the browser's cryptographic random source rather than Math.random, so collisions stay theoretical.

Works offline, no sign-up

Everything is generated locally, so nothing is uploaded and the page works with no connection.

Frequently asked questions

Are the UUIDs generated privately?

Yes. They are created in your browser using a cryptographically secure random source, with nothing uploaded. It works offline once loaded.

What is the difference between v4 and v7?

Version 4 is completely random, which is the most common type. Version 7 starts with a timestamp, so the IDs sort in the order they were created, which is useful as database keys.

Are these safe to use as unique identifiers?

Yes. Random version 4 UUIDs have an astronomically small chance of collision, so they are widely used as unique keys.

Can I generate many at once?

Yes, up to 1000 at a time. You can format them in uppercase, without hyphens, or wrapped in braces, then copy or download the list.

What is the Nil UUID?

The Nil UUID is all zeros and is sometimes used as a placeholder or default empty value.

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