UUID Generator
Generate random UUID v4 identifiers instantly.
Runs entirely in your browser. Nothing is sent to a server.
Save this tool
Keep UUID Generator handy
Use your browser's Share menu, then “Add to Home Screen”.
About this tool
A UUID is a 128-bit identifier you can generate anywhere without asking a central server whether it is already taken. Version 4 UUIDs are made from random data, which is why two independently generated values essentially never collide, and why they are the usual choice for database primary keys, idempotency keys, correlation ids in logs, and filenames for uploaded content. This generator uses your browser's built-in cryptographic random number source rather than a weaker pseudo-random one, so the values are suitable for production use. Nothing is transmitted or recorded: the identifiers are created locally and exist only in your browser until you copy them.
How to use it
- Choose how many identifiers you need
- Click Generate
- Copy the result
Frequently asked questions
Are these UUIDs safe to use in production?
Yes. They come from the browser's cryptographic random source via crypto.randomUUID(), which is the same primitive server-side libraries rely on, rather than a weaker Math.random() based approach.
Could two of these ever collide?
In practice, no. A version 4 UUID has 122 random bits, so you would need to generate billions per second for many years before a collision became likely enough to plan around.
Should I use a UUID as a database primary key?
It depends. UUIDs let you create records without a round trip to the database and avoid exposing sequential counts, but they are larger than integers and random ordering can hurt index locality on very large tables.