UUID Generator
A UUID is a 128-bit identifier written as 36 characters, designed so that separate systems can mint ids independently without coordinating and still not collide. That property is what makes them useful for distributed systems, offline clients and merged datasets.
This generator produces version 4 UUIDs, which are essentially random, for use as keys, correlation ids or test data.
Runs in your browser. UUID Generator processes your input on your own device. Nothing you enter or upload is sent to a server.
How to use the UUID Generator
- Open the generator.
- Generate one or more UUIDs.
- Copy the values you need.
Frequently asked questions
What is a version 4 UUID?
One whose bits are random apart from the small fixed portion identifying the version and variant. Other versions derive their value from a timestamp, a MAC address or a hash of a name instead.
Can two UUIDs ever collide?
In principle yes, but the space is 122 random bits, so the probability is negligible for any realistic number of ids. They are treated as unique in practice.
Are UUIDs a good primary key?
They are excellent when ids must be generated by clients or by several services at once. The trade-off is that random keys scatter writes across a B-tree index and take more space than an integer, which is why some databases prefer time-ordered id schemes for large tables.