UUID generator
Generate version 4 UUIDs, as many as you need.
A version 4 UUID is a 122-bit random identifier, unique enough that you can generate one anywhere without asking a database. These come from the cryptographic generator built into the browser rather than from Math.random, which is the usual mistake: the two look identical and only one of them is unpredictable.
How to use it
- Say how many you need.
- Press Generate.
- Copy one, or all of them.
Why use this tool
Completely private
Everything runs inside your browser. Your files and text are never sent to a server.
Free, with no limits
No sign-up, no watermarks and no cap on how many times you can use it.
Instant results
There is no upload or queue to wait for, so results appear as fast as your device can work.
Works on any device
Runs in any modern browser on phone, tablet or desktop. Nothing to install.
Frequently asked questions
- Are these really random?
- They come from the cryptographically secure generator in your browser, the same source used for keys. A UUID built from Math.random looks the same and is predictable, which matters the moment one is used as a token.
- Could I get a duplicate?
- In practice, no. There are about 5.3 times 10 to the 36th possible values; you would need to generate billions per second for decades before a collision became likely.
- Should I use a UUID as a database key?
- It works and avoids coordinating ids across systems, but a random v4 scatters writes across an index and can slow inserts on large tables. Many teams use v7, which is time-ordered, for exactly that reason.
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