A short companion for UUID Generator: when it is useful, what it expects, and what to check before using the result.
What it does
Generate version 4 UUIDs, one at a time or in bulk, using the browser's cryptographic random number generator. They are suitable for database keys, request IDs and anything else that has to be unique without coordinating with a central authority.
Use the tool
Open UUID Generator, add the input the tool asks for, run it, and check the output before using it elsewhere.
Input and output
- Input: text.
- Output: text.
- Category: Crypto.
Privacy and processing
Processing happens locally in your browser. This tool does not upload the input to ilham.dev.
Questions
Can two generated UUIDs collide?
A v4 UUID carries 122 random bits. You would need to generate around 2.7×10^18 of them before a collision became likely, which is far beyond any realistic workload.
Are these UUIDs predictable?
No. They come from crypto.getRandomValues rather than Math.random, so earlier values tell you nothing about later ones.
Related guide
For broader background, see IDs and Test Data.