UUID Generator
Create unique IDs in bulk: UUID v4, UUID v7 or ULID.
How to use the UUID Generator
- Pick UUID v4, UUID v7 or ULID.
- Choose how many you need, up to 1,000 at a time.
- Adjust the format: uppercase, without hyphens, in braces or quoted for code.
- Copy them all or save as a text file. Click Regenerate for a new batch.
About this tool
A UUID (also called a GUID) is a 128-bit identifier written as 32 hexadecimal digits, such as 3f2b8c1e-9a4d-4e7b-b1c2-5d6e7f809a1b. Because there are so many possible values, systems can create IDs independently without coordinating and still never clash in practice. They are used for database keys, file names, request IDs and anything else that needs a unique label.
Version 4 is fully random (122 random bits from your browser's secure generator). Version 7, defined in RFC 9562, puts a millisecond timestamp in the first 48 bits and fills the rest with random data, so new IDs sort after older ones. That keeps database indexes compact and makes IDs roughly chronological. A ULID follows the same idea but is written as 26 Crockford Base32 characters, which is shorter and avoids ambiguous letters.
Tip: if you are choosing a primary key for a new database table, UUID v7 or ULID usually performs better than v4 because inserts land at the end of the index instead of scattering across it.
Frequently asked questions
Are these IDs generated on a server?
No. They are created in your browser using the Web Crypto random number generator. Nothing is sent or logged, and we never see the IDs.
Can two UUIDs ever be the same?
In theory yes, in practice no. With v4 you would need to generate billions of IDs every second for many years before a duplicate became even slightly likely.
What is the difference between UUID v4 and v7?
v4 is completely random. v7 starts with the creation time in milliseconds, so IDs sort in the order they were made. Both are the same length and format.
Are the IDs in one batch in order?
Yes for v7 and ULID. When several are created within the same millisecond, a counter keeps them strictly increasing, so sorting them gives the generation order.
Is a GUID the same as a UUID?
Yes. GUID is Microsoft's name for the same 128-bit format. Use the braces option for the {…} style common in Windows and .NET code.