UUID Generator – v4 and v7 in Bulk

A UUID, or universally unique identifier, is a 128-bit value written as 32 hex digits in five groups, such as 123e4567-e89b-42d3-a456-426614174000. It lets systems create IDs independently without a central counter and without clashing in practice.

They are the same thing. GUID is the name used in Microsoft and .NET environments, while UUID is the standard name. Both use the same 128-bit format.

Choose UUID v4 or v7, set how many you want, and the list is created straight away. Click Generate for a fresh batch, then copy the values or download them as a text file.

A version 4 UUID is made almost entirely of random bits, apart from a few bits that mark the version and variant. It is the most widely used type and is a good default for primary keys, tokens in test data and general unique IDs.

A version 7 UUID starts with a millisecond timestamp followed by random bits, so values created later sort after earlier ones. This makes them friendlier to database indexes than random v4 values, and a good choice for new tables that are sorted by creation time.

The random bits come from the secure random number generator built into your browser, which makes a clash extremely unlikely. For v4 the chance of two matching values is so small that it is ignored in practice.

Do not use a UUID as a password or secret key. They are designed to be unique, not to be hard to guess in every situation, and v7 values contain a readable timestamp. Use a proper token or password generator for secrets.

You can generate from 1 up to 1,000 at a time. The default is 5, and the list updates when you change the amount or any option.

Yes. Untick the hyphens option to get 32 characters with no dashes, tick uppercase for capital letters, and tick braces to wrap each value in curly brackets, a style some Windows tools expect.

Random v4 values spread new rows across an index, which can slow inserts in large tables. Time-ordered v7 values are appended near the end, which usually keeps indexes more compact and inserts faster.

No. UUIDs are generated in your browser and never uploaded or stored, so you can create test data and IDs privately.

Yes. It is free with no sign-up and no limits, and it works on phones, tablets and desktop browsers.