UUID Generator

About UUID Generator

UUID Generator creates random version 4 UUIDs and time-ordered version 7 UUIDs online, from one up to 1,000 at a time. Toggle uppercase or remove hyphens to match the format your code expects, then copy a single UUID or all of them at once, or download the list as a text file. A fresh v4 UUID is ready as soon as the page opens. IDs are generated in your browser with the Web Crypto random number generator. Developers use it to get GUIDs for database primary keys, test fixtures, API requests and config files. Pick v7 when you want IDs that sort by creation time, or v4 when you just need a unique random ID.

How to use

1. Enter how many IDs you need in the Number of UUIDs field, from 1 to 1,000.
2. Choose V4 for random UUIDs or V7 for time-ordered UUIDs.
3. Click Generate UUIDs, or press Enter in the count field, to create the list; one v4 UUID is already generated when the page loads.
4. Toggle Uppercase or No Hyphens to reformat the generated IDs instantly.
5. Click Copy next to a single UUID, Copy All to copy the whole list, one per line, or Download to save it as uuids.txt.

Limitations & notes

• Up to 1,000 UUIDs can be generated at a time; an empty or out-of-range count is corrected to 1 to 1,000 when you generate or leave the field.
• V7 UUIDs embed their creation time in milliseconds, so anyone holding the ID can tell when it was made.
• V7 IDs created within the same millisecond are not guaranteed to sort in generation order.
• Changing the version does not update the current list until you click Generate again; Uppercase and No Hyphens reformat the existing list.
• If the browser lacks the Web Crypto API, random bits fall back to Math.random, which is not cryptographically secure.

FAQ

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit value written as 32 hex digits in five hyphen-separated groups, like 550e8400-e29b-41d4-a716-446655440000. It can be generated anywhere without a central authority and is practically guaranteed to be unique.

What is the difference between UUID v4 and v7?

v4 is fully random apart from version bits. v7 starts with a millisecond Unix timestamp followed by random bits, so v7 IDs sort by creation time, which makes them friendlier for database indexes.

Is a UUID the same as a GUID?

Yes. GUID is Microsoft's name for the same 128-bit identifier format; the terms are used interchangeably.

Can two generated UUIDs collide?

In theory, but the odds are negligible. A v4 UUID has 122 random bits, so you would need to generate about a billion per second for roughly 85 years to reach a 50% chance of a single collision.