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Random Number Generator

Enter a from-to range and draw a fair random number - no rounding bias, via cryptographic randomness right in your browser.

Verifiably fair: The draw uses your browser's cryptographic random generator (crypto.getRandomValues) instead of a simple pseudo-random one - the same mechanism encryption relies on. Every possible outcome is exactly as likely as the weights say, with no bias from rounding. Everything runs locally in your browser; there is no server that could influence or manipulate the result.

In 3 steps

  1. Enter the "from" and "to" values.
  2. Draw a random number.
  3. See the result, and draw again if needed.

History

No result yet.

    Everything stays on your device: no account, no server, exportable and deletable at any time.

    Is my file uploaded?

    No. Everything runs in your browser - your file never leaves your device. How this is verifiable

    No upload100% local
    Your content stays with youno third-party access
    Hosted in GermanyGlobal Content Delivery
    Independently auditedTLS A+ · HTTP headers A+

    The random number generator draws a whole number from a from-to range you choose yourself - for example for lottery-style decisions, sampling, or random moves in games. Enter the range, draw, done.

    To make every number in the range exactly equally likely, the tool uses rejection sampling on top of your browser's cryptographic random generator (crypto.getRandomValues): random values that would cause bias via a simple modulo remainder are discarded and redrawn, rather than accepting a slightly skewed distribution.

    Every drawn number lands in your local history - exportable and deletable with one click, without any server ever seeing it.

    Specifications

    Specifications
    Input formatsNo file (generator)
    Batch processingNo
    ProcessingLocally in your browser (JavaScript)
    File uploadNone

    Limitations: Whole numbers are drawn; "from" must be less than or equal to "to". The range stays within the browser's safe integer bounds. Everything runs locally, with no server involved.

    FAQ

    Are my draws uploaded or stored?

    No, everything runs locally. Your draw history lives in your browser storage, exportable and deletable at any time.

    Why not just use Math.random()?

    crypto.getRandomValues provides cryptographically strong randomness instead of a simpler, more predictable pseudo-random source - and combined with rejection sampling, no bias from rounding at the range edges occurs.

    Can "from" be greater than "to"?

    No - the tool honestly reports that as an error instead of silently swapping the values.

    Are negative numbers possible as a range?

    Yes, e.g. -10 to 10 - as long as "from" is less than or equal to "to".

    How is this different from the dice tool?

    The dice roller follows NdM game notation (multiple dice, a fixed side count); the random number generator draws a single number from a freely chosen range.

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