About this tool
This tool generates random version-4 UUIDs, up to 100 at a time. It uses your browser's cryptographic random source — crypto.randomUUID where available, and a getRandomValues fallback that sets the version and variant bits explicitly — so the output is suitable for production identifiers, not just placeholders.
UUIDs are useful when several systems need to mint identifiers without coordinating. A version-4 UUID carries 122 random bits, so collisions are not a practical concern: you can generate keys on a client, in a batch job and in a database at the same time and merge the results safely. Generation happens entirely in your browser and no value is recorded anywhere. Where identifier strategy causes problems at the database layer, that is territory our Oracle database & DBA support team covers.
How to use it
The tool generates a batch on page load and regenerates on demand.
- Set how many UUIDs you need, from 1 to 100.
- Select Generate; the list is replaced each time.
- Copy the values you want directly out of the result panel.
- Use them as primary keys, correlation IDs for tracing, idempotency keys for API requests, or test fixtures.
Common questions
What is the difference between UUID v4 and v1?
Version 4 is random: essentially all of its bits come from a random source, and it carries no information about when or where it was created. Version 1 is time-based, derived from a timestamp and the host MAC address, which makes it roughly sortable but leaks those details. This tool produces version 4.
Can two v4 UUIDs collide?
In theory yes, in practice no, provided the random source is sound. With 122 random bits you would need to generate on the order of a billion UUIDs per second for decades before a collision became likely.
Are v4 UUIDs a good database primary key?
They work, but random keys scatter inserts across a B-tree index and can fragment it. Where insert throughput matters, consider a time-ordered format such as UUIDv7, or keep the UUID as an external identifier alongside an internal sequential key.