How This Random Number Generator Works

Unlike basic generators that rely on Math.random(), this tool uses your browser's built-in Web Crypto API (crypto.getRandomValues) — the same source of randomness used for encryption keys and secure passwords. Numbers are drawn with rejection sampling, a technique that guarantees every value in your range has exactly the same probability of appearing, with no modulo bias. Everything runs entirely in your browser: nothing is sent to a server, and no results are stored.

What Can You Use Random Numbers For?

Random numbers are useful anywhere fairness or unpredictability matters. Pick raffle and giveaway winners by assigning entries a number and generating one in that range. Roll virtual dice or generate values for board games, RPGs, and classroom activities. Researchers and analysts use random numbers for statistical sampling — the "unique" option makes it easy to select a random subset of participants or rows without duplicates.

You can generate a single number or up to 10,000 at once, constrain the range with any minimum and maximum (negative numbers work too), remove duplicates, and sort the output. The count, sum, and average of multi-number results are calculated automatically, and one click copies everything to your clipboard.