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Random Number Generator

Generate a random whole number in a range you choose, using the browser's cryptographic random source.

Details

Numbers come from the browser's cryptographic random source.

Your Results

What Random Number Generator does

Picking a number without bias is harder than it looks: people asked to choose randomly favour certain digits heavily, and simple software generators can be predictable.

This draws from the browser's cryptographic random number generator and samples the range without modulo bias, so every value in the range is equally likely.

  • Any minimum and maximum, inclusive of both
  • Cryptographically secure random source
  • Generate button for a fresh draw

How to use Random Number Generator

  1. 1

    Set the range

    Both the minimum and maximum can be produced.

  2. 2

    Generate

    Each press produces an independent draw.

When to use it

Picking a winner

Number the entries and draw one. For anything where fairness must be demonstrable to others, use a method that leaves an auditable record.

Sampling

Select rows, files or records at random rather than taking the first ones, which are rarely representative.

Breaking a deadlock

An unbiased draw when a decision genuinely does not matter and nobody wants to make it.

Limits and known behaviour

  • Draws are independent, so the same number can appear twice in a row. That is what randomness looks like, not a fault.
  • Only whole numbers are produced.
  • There is no option to draw several unique values at once, which is what a raffle or a lottery-style draw needs.
  • There is no history of previous draws.
  • For a formal draw where fairness must be demonstrated to others, use a method that can be independently audited; nothing here produces a verifiable record.

Privacy and data handling

Runs entirely in your browser

  • The calculation runs in this page. Nothing you enter is transmitted or stored.
  • The tool works offline once the page has loaded.

Site-wide data handling, including analytics and advertising, is described in the privacy policy.

Frequently asked questions

Is this genuinely random?

It uses the browser's cryptographically secure generator, which is seeded from operating-system entropy and is not predictable in practice. It is technically pseudorandom, which is the standard used for cryptographic key generation.

Why did I get the same number twice?

Because each draw is independent. In a range of ten, a repeat happens about one time in ten. Runs and repeats are expected in random sequences, and their absence would be the suspicious result.

How do I draw several different numbers?

Draw one at a time and discard any repeat, or number your items and shuffle the list instead. This tool draws with replacement, so it cannot guarantee distinct values on its own.

Can I use this for a prize draw?

For an informal one, yes. For anything where you must be able to show the draw was fair, use a method that produces a record participants can verify afterwards; nothing here logs what was drawn.