UUID Generator
Generate random UUID v4 or time-ordered UUID v7 values, one at a time or hundreds at once. Choose uppercase, with or without hyphens, and copy a ready-to-use list for databases, APIs and tests.
From 1 to 500
What is a UUID?
A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit identifier written as 32 hexadecimal digits in five groups: 8-4-4-4-12. It lets any system create unique IDs without asking a central database, which is why UUIDs are used as primary keys, order IDs, file names and correlation IDs.
UUID v4 or UUID v7?
- UUID v4 has 122 random bits. It is the most common version and reveals nothing about when or where it was created.
- UUID v7 starts with a millisecond timestamp (RFC 9562), so IDs sort in creation order. That keeps database indexes faster than with random v4 values.
How to generate UUIDs
- Pick the version: v4 (random) or v7 (time-ordered).
- Enter how many UUIDs you need, up to 500 at once.
- Adjust the format: uppercase and with or without hyphens.
- Copy a single UUID or the whole list, one per line.
UUID example
A UUID v4 looks like this: 3f2b8c9e-1a4d-4f6b-9c2e-7d5a1b8e4f03. The 4 at the start of the third group is the version, and the first digit of the fourth group (8, 9, a or b) is the variant.
crypto.getRandomValues, the system's cryptographic random generator. Nothing is sent to a server.Frequently asked questions
Are UUID and GUID the same thing?
Yes. GUID (Globally Unique Identifier) is Microsoft's name for the same 128-bit identifier standard.
Can a UUID be duplicated?
Not in practice. A UUID v4 has 122 random bits, so you would need to generate billions of UUIDs per second for decades to have a real chance of a collision.
What is the difference between UUID v4 and v7?
v4 is fully random. v7 starts with a millisecond timestamp, so IDs sort in creation order, which improves database index performance.
Should I use UUIDs as primary keys?
You can. Prefer UUID v7 for large tables, because time ordering avoids index fragmentation. In PostgreSQL, use the uuid type instead of text.
How many characters are in a UUID?
36 characters with hyphens, or 32 hexadecimal digits without them.