Generators
Random Number Generator
Generate random integers or decimals in a custom range, one at a time or in bulk, using cryptographically secure randomness.
Type
or press R
Results
Why not just use Math.random()?
Math.random() is fine for casual use (like a UI animation) but isn't cryptographically secure and isn't specified to be uniformly distributed across implementations. This tool uses crypto.getRandomValues(), the same CSPRNG-backed API used to generate encryption keys, so results are suitable for anything short of generating actual secrets (for those, generate the secret directly withcrypto APIs rather than mapping it through a number range).
Common use cases
- Picking a random sample size, test seed, or A/B bucket during development
- Generating dummy/test data
- Simple randomized decision-making (dice rolls, draws, shuffles)
Frequently asked questions
- How random are these numbers?
- Numbers are generated with the Web Crypto API's crypto.getRandomValues(), a cryptographically secure pseudo-random number generator (CSPRNG) — suitable for far more demanding uses than Math.random(), such as tokens or sampling.
- Is the range inclusive?
- Yes — both the minimum and maximum you enter are possible results, for both integers and decimals.
- How many numbers can I generate at once?
- Up to 1,000 per click, one per line in the results box.
- Does anything get sent to a server?
- No — all randomness is generated and stays entirely in your browser.