Random Number Generator

What is a Random Number Generator?

A random number generator picks numbers with no predictable pattern. This tool uses the browser's cryptographic random source, which is far more random than the pseudo-random generators used in most software. Common uses include picking lottery numbers, choosing a random winner, games, and statistics.

How It Works

Each number is generated using the Web Crypto API:

1. Call crypto.getRandomValues() for a random 32-bit integer
2. Map the result into the requested range [min, max]
3. If "no duplicates" is on, reject and retry any repeats
4. Nothing is logged, stored, or transmitted

Tips

  • For a coin flip, set min to 0 and max to 1. Or use the dedicated Coin Flipper.
  • For a dice roll, set min to 1 and max to 6. Or use the dedicated Dice Roller.
  • "No duplicates" requires the range to be large enough to fit all the requested numbers.
  • You can generate up to 100 numbers at once.

Frequently Asked Questions

Is this truly random?

It uses crypto.getRandomValues(), which is cryptographically secure and unpredictable. This is the same source used for generating passwords and cryptographic keys. It is far stronger than Math.random(), which is only pseudo-random.

What does "no duplicates" mean?

Each generated number will appear at most once in the result set. Useful when picking lottery numbers or choosing multiple unique winners. The range must have at least as many integers as the count you request.

Can I generate negative numbers?

Yes. Set min to a negative value like -100 and max to 100. The generator handles any integer range.

Does it remember my previous settings?

Not across page loads, but the history list shows results from your current session. Refresh the page to reset everything.