UUID generator
Make random or time-ordered UUIDs, one or a thousand at a time.
See whether it’s valid, which version it is and, for time-based UUIDs, when it was made.
Report a problem with this tool
How to use UUID generator
Pick a version
Version 4 is random and fits almost everything. Version 7 starts with the time, so it sorts well as a database key.
Choose how many
Make 1 to 1,000 at once, in upper case, without hyphens, or quoted for pasting into code.
Copy or download
Copy the list or save it as a text file. Click Generate new for a fresh batch.
Why use Utils365
Secure randomness
UUIDs come from your browser’s cryptographic random generator, the same one used for keys and tokens.
Version 7 done right
v7 UUIDs follow RFC 9562 and stay in order even when many are made in the same millisecond.
Check any UUID
Paste a UUID to see whether it’s valid, its version and variant, and when a time-based one was made.
Private by design
Everything happens in your browser, so the UUIDs you make are never sent anywhere or stored.
Frequently asked questions
What is a UUID?
A 128-bit identifier written as 32 hex digits in groups of 8-4-4-4-12, such as 550e8400-e29b-41d4-a716-446655440000. It’s also called a GUID. UUIDs can be made anywhere without a central list and still won’t clash.
What’s the difference between UUID v4 and v7?
Version 4 is 122 random bits. Version 7 starts with the time in milliseconds followed by random bits, so newer UUIDs sort after older ones. That keeps database indexes tidy and fast.
Which UUID version should I use for a database primary key?
Version 7 is usually the better choice. Because the values grow over time, new rows go at the end of the index instead of being scattered, which means fewer page splits and better caching.
Can two UUIDs ever be the same?
In practice, no. With 122 random bits you would need to make about a billion UUIDs every second for 85 years to have even a 50% chance of one repeat.
Is a GUID the same as a UUID?
Yes. GUID is Microsoft’s name for the same thing. Windows often shows GUIDs in upper case inside braces, like {550E8400-E29B-41D4-A716-446655440000}. The checker accepts that form too.
Can I get the date from a UUID?
Only from time-based versions: 1, 6 and 7. Paste one into Check a UUID to see when it was made. Version 4 is entirely random, so it holds no date.