Free tool
UUID Generator: Version 4, Version 7 and a Validity Checker
Make one UUID or a thousand, pick the version and the format, and paste any UUID into the checker to see what it is. Facts about the standard were read from RFC 9562 on 22 October 2026.
Version 7 puts the time first, so new rows land at the end of a database index instead of all over it.
UUIDs are made in your browser and are not stored or sent anywhere. Only your format choices are kept on your own device.
How the generator works
Choose a version at the top, press Make new, and the UUID appears in large type with a Copy button. Set how many you want in the side column and the full list fills the box below, ready to copy or save as a text file. The same column lets you remove the dashes, switch to capital letters, and wrap each one in quotes, braces or a urn prefix, so the list can go straight into code, a spreadsheet or a test fixture.
The checker at the bottom reads any UUID you paste. It tells you whether the text is valid, which version it is, and, for the versions that carry a time, when it was made.
Which version to choose
| Version | What it holds | Good for |
|---|---|---|
| 4 | 122 random bits, plus 6 bits that mark the version and variant | Identifiers where nobody needs to read order from the value |
| 7 | A 48-bit Unix timestamp in milliseconds at the front, then random data | Database keys, since new values sort after old ones |
| Nil | All 128 bits set to zero | A placeholder that means no UUID |
These details come from RFC 9562, published in May 2024, which replaces RFC 4122. It says a version 7 UUID suits database keys and sorting because it is time-ordered and sorts as raw bytes. The standard text form is 32 hexadecimal digits in groups of 8, 4, 4, 4 and 12, joined by hyphens. Source: RFC 9562, read 22 October 2026.
Using the output well
- Keep the dashes unless a system asks for the bare 32 digits, since the grouped form is what most tools expect.
- Use the quote and comma option to build an array of strings for a test, or the braces option for systems that write GUIDs that way.
- Treat a UUID as an identifier, not a secret. Do not use one as a password or an access token.
- If a database sorts by the key, a time-ordered version groups recent rows together, which is why many teams choose version 7 for new tables.
The list is made with your browser's secure random generator, so you can make large batches without any request leaving the page.
Mistakes people make with identifiers
Most trouble with UUIDs comes from how they are stored, not how they are made. A few habits avoid it.
- Storing them as long text. A UUID is 128 bits. Many databases have a native type for it, which is smaller and faster to compare than a 36-character string.
- Mixing cases. Capital and lower case letters mean the same value, but a plain text comparison treats them as different. Pick one form and keep it, which is why the case switch sits in the settings.
- Hiding order information in the value. A version 4 value carries no order. If you need to know which record came first, store a date as well, or choose version 7.
- Showing them in public addresses without thought. A UUID in a web address is hard to guess, but it is not a lock. Check permissions on the server for every request.
If you only need a handful for a design mock-up or a test, the single UUID at the top is enough. For a seed file, set the count in the side column and save the list as a text file.
Where this comes up in website work
Form builders, headless CMS entries, order numbers and test data often need unique identifiers. When we plan a migration or an integration, matching identifiers between systems is one of the checks we write down early. Our Webflow integration page describes the kind of connections we build.
Frequently asked questions
What is a UUID?
A UUID is a 128-bit identifier, usually written as 32 hexadecimal digits in five groups separated by hyphens. It is made so that two systems can create identifiers without checking with each other first.
What is the difference between version 4 and version 7?
Version 4 is almost all random, with 122 random bits. Version 7 starts with a 48-bit millisecond timestamp, so values made later sort after values made earlier.
Can two UUIDs be the same?
It is possible in theory, but with 122 random bits in version 4 it is not a practical worry for ordinary use.
Is a UUID safe to use as a password?
No. A UUID is an identifier. Anything secret needs a proper password or token generated for that purpose.
What is the nil UUID?
It is the value with every bit set to zero. RFC 9562 describes it as a placeholder for no UUID.
Does the tool send my UUIDs anywhere?
No. They are made in your browser, and only your format settings are saved on your own device.
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