Random Number Generator

Generate random numbers free online using a cryptographically secure source. Set a custom range, generate multiple numbers at once, and exclude duplicates if needed.

Minimum

Maximum

How many: 1 No duplicates

Uses crypto.getRandomValues() -- a genuinely secure random source.

How to Use This Tool

Set your rangeEnter the minimum and maximum values

Choose how many numbersSlide to pick how many numbers to generate at once

Generate and useClick Generate to get your random number(s)

True Randomness Versus "Good Enough" Randomness

For picking a random number to settle a casual decision, almost any randomness source works fine. For anything where fairness genuinely matters -- a contest, a fairness-sensitive raffle, a sampling method for research -- the underlying randomness source is worth getting right, which is why this generator uses crypto.getRandomValues() rather than the more commonly used Math.random().

Set a range, choose how many numbers you need, and optionally require uniqueness across the batch -- useful for drawing several distinct winners or sample IDs without manually checking for accidental repeats.

Why Uniqueness Matters for Certain Use Cases

Drawing five raffle winners from a pool of 100 entries needs five distinct numbers -- a repeat would mean the same entry winning twice, or needing to manually re-roll. The no-duplicates option handles this automatically, generating a set of genuinely distinct values within your specified range.

Range Limits in Practice

Standard JavaScript number precision comfortably covers any range a typical use case would need, from single-digit dice-roll ranges to large numeric pools well into the millions, without any practical precision loss for integer ranges.

Frequently Asked Questions

Yes. It uses crypto.getRandomValues(), the Web Crypto API's cryptographically secure random number generator, rather than the more common Math.random(), which is not designed for situations where unpredictability genuinely matters.

Yes, enable the no-duplicates option to generate a set of unique numbers within your range -- useful for things like raffle drawings or selecting unique sample IDs without manual checking for repeats.

Selecting random survey respondents for follow-up, picking a winner from a numbered list of entries, generating test data with specific numeric ranges, or settling a decision between a few options assigned numbers.

Practically, any range within standard JavaScript number precision works reliably, which covers virtually any everyday use case from small dice-roll ranges to large six and seven-digit number pools.

For low-stakes personal use, it rarely matters in practice. For anything with real consequences -- a contest with a prize, a fairness-sensitive selection -- using a properly random source rather than a predictable one is the more defensible choice, even if the practical risk of Math.random() being exploited is low for casual use.