UUID Generator
This UUID generator creates random version 4 UUIDs, one at a time or in batches of 10 or 25, using the browser's cryptographically secure random number generator.
About this tool
This UUID generator creates random version 4 UUIDs, one at a time or in batches of 10 or 25, using the browser's cryptographically secure random number generator.
How to use it
- Click Generate UUID for a single UUID.
- Click Generate 10 or Generate 25 for a list, one per line.
- Click Copy All to copy the output.
Good to know
- A UUID is a 128-bit identifier written as 32 hexadecimal digits in the pattern 8-4-4-4-12.
- Version 4 UUIDs are random: 122 of the 128 bits are random, and the rest mark the version (4) and variant.
- UUIDs are specified in RFC 9562 (which replaced RFC 4122); GUID is Microsoft's name for the same format.
- The chance of two random v4 UUIDs colliding is negligible for practical purposes.
Runs entirely in your browser — nothing you enter is uploaded or stored.
Frequently asked questions
What is the difference between a UUID and a GUID?
They are the same thing. GUID (globally unique identifier) is the term Microsoft uses for a UUID.
Can two generated UUIDs ever be the same?
In theory yes, but with 122 random bits the probability is so small that it can be ignored in real systems.
Are these UUIDs safe to use as database keys?
Yes, v4 UUIDs are widely used as primary keys. Some databases index time-ordered UUIDs (v7) more efficiently, but v4 works everywhere.
Are the UUIDs generated on a server?
No. They are generated in your browser with crypto.getRandomValues and never sent anywhere.