Numbers ·By Aisha Khan
How Random Number Generators Actually Work
A plain-English look at what happens when you click generate, from seeds and entropy to the browser's crypto API.
Every time you click Generate on Toolssy, a surprising amount of maths runs in a fraction of a second. This guide breaks it down without the jargon.
Seeds and entropy
A software random number generator starts from a seed, an unpredictable starting value. Modern browsers gather entropy from hardware events and expose it through the Web Crypto API.
Pseudo vs. true randomness
Most generators are pseudo-random: deterministic algorithms that produce sequences which look random. For everyday tasks, this is more than enough.
The takeaway
You don’t need to understand the maths to trust the result, but now you know what’s happening under the hood.