About UUID Generator
This UUID generator creates random version 4 UUIDs, also called GUIDs, in the standard 8-4-4-4-12 format. Choose how many you need, from 1 to 500, and the list updates immediately. You can switch the output to uppercase or remove the dashes to get a plain 32-character hex string. Every click on Generate produces a fresh list, so you can repeat it until you have enough.
Each UUID is built from your browser's cryptographically secure random number generator, with the version and variant bits set as the version 4 specification requires. Nothing is requested from a server and nothing is stored, so you can generate identifiers for test data, database keys or fixtures freely. Copy the list and paste it wherever you need it.
How to use UUID Generator
- 01
Choose how many UUIDs you need.
- 02
Optionally uppercase them or remove dashes.
- 03
Copy the list.
When to use it
- Creating primary keys or ids for seed data and database fixtures.
- Generating unique request or correlation ids to trace calls across services.
- Filling a spreadsheet or JSON mock file with many distinct identifiers.
- Producing dashless 32-character ids for systems that do not accept hyphens.
- Making throwaway unique names for test files, queues or storage buckets.
Frequently asked questions
Are these UUIDs really unique?
They come from the browser's cryptographic random source and carry 122 random bits, so the chance of two matching is extremely small. Uniqueness is statistical rather than guaranteed by a central authority.
Which UUID version does this tool generate?
Only version 4, the random kind. Versions based on time or names, such as v1, v5 or v7, are not offered here. You can see the version digit 4 at the start of the third group.
How many UUIDs can I generate at once?
Between 1 and 500 per click. Values outside that range are adjusted to the nearest limit. Click Generate again to get a fresh list, or change the count or format options.
What is the difference between a UUID and a GUID?
In practice there is none. GUID is the term mostly used in Microsoft environments, while UUID is the standard name. Both use the same 128-bit format, and the tool offers uppercase output if your system expects it.
Can I remove the dashes?
Yes. Tick Remove dashes to get 32 hexadecimal characters with no hyphens, and tick Uppercase for capital letters. Both options can be combined and are applied to the whole list.
Are the UUIDs sent or saved anywhere?
No. They are generated locally in your browser and not uploaded or logged by i40x. The tool is free with no sign-up and no usage limit. Results are not saved or logged.