Random Generator
Random strings, random numbers, or a pick from your own list.
By opening this website or using its tools, you agree to our Terms and Privacy Policy.
Your file never leaves your browser during processing
How it works
To generate something random, pick String, Number, or Pick from list above and set the options — the result is drawn from your browser’s cryptographically secure random generator and never leaves the page.
All three modes here draw from the same source: crypto.getRandomValues with rejection sampling, rather than Math.random, which browsers explicitly do not guarantee is unpredictable. Rejection sampling matters specifically for the number and pick modes — a naive `random() % range` very slightly favors low values whenever the range doesn’t divide evenly into the generator’s output space, which would make "random" number-in-a-range generation subtly biased.
The "no repeats" option behaves differently depending on the mode. For numbers, it draws distinct values one at a time into a set until enough are collected, rather than building an array of every possible number first — that keeps a request like "50 unique numbers between 1 and a billion" fast and memory-light. For the list picker, "no repeats" is a partial Fisher-Yates shuffle: the whole list is shuffled and the first N items are taken, which is the standard unbiased way to sample without replacement.
The list picker also lets you shuffle your pasted list in place, useful for randomizing an order (seating, review order, task assignment) rather than picking a subset out of it.
FAQ
Is this the same randomness source as the password generator?
Yes. Both use crypto.getRandomValues via the same rejection-sampling helper, so neither favors any outcome over another.
How does "no repeats" work for numbers over a huge range?
It draws random numbers one at a time and keeps only distinct ones, rather than generating every possible value up front — so picking 20 unique numbers out of a billion is just as fast as picking them out of 100.
Can I use this to randomize a list order instead of picking a subset?
Yes — the "Shuffle the whole list" button in Pick from list mode reorders every item rather than selecting a subset.