Secure random numbers for people and software

Random Number Generator

Generate integers or decimals with precise controls, clear statistics and downloadable results. The tool uses cryptographically strong browser randomness and keeps recent draws only in this tab.

◆ Cryptographically strong randomness

Integers, decimals and unique draws

Configure your random draw

Choose a quick preset or set the range, amount, uniqueness, parity and ordering yourself.

Quick presets

Secure draw completed

Generated numbers

Every value is sampled uniformly from the eligible values in your selected range.

Result statistics

Count–

Unique–

Minimum–

Maximum–

Sum–

Mean–

Median–

Distribution snapshot

Bars show frequencies for individual values or equally sized intervals. A small sample will not look perfectly even.

Recent draws in this tab

The last five draws stay only in this browser tab and disappear when it is closed or reloaded.

Generate a result to start the temporary history.

How secure and unbiased generation works

Web Crypto in the browser

The interactive calculator uses crypto.getRandomValues rather than Math.random(). Values that could introduce modulo bias are discarded and sampled again.

Sampling without replacement

For unique draws, Floyd’s algorithm selects the requested number of distinct positions without slowing down near the end of a large draw.

Clear limits

The tool permits at most 1,000 results and validates every range. These limits keep the page responsive even when a large set is requested.

Random is not a prediction

Every eligible value has the same probability in a uniform draw. Previous results do not make a future value more or less likely.

Useful ways to use random numbers

Games and fair draws

Choose turn order, dice outcomes, teams, winners or classroom questions from a known range.

Testing and sample data

Create bounded values for spreadsheets, software tests, examples and demonstrations.

Statistics and simulations

Build independent uniform samples, then inspect the observed mean, median and frequency chart.

Creative prompts

Randomly select a page, topic, exercise, colour index or challenge when you want an unbiased starting point.

Important limitations

This generator is suitable for fair general-purpose draws and technically strong random samples. Do not use a simple number draw as a password, encryption key, regulated lottery system, gambling service or substitute for audited specialist software.

Random Number Generator FAQ

Are the generated numbers cryptographically strong?

The calculator uses Web Crypto in the browser and does not use Math.random() to generate results.

Can the generator include negative numbers?

Yes. Enter a negative minimum, a positive or negative maximum, and choose integer or decimal mode.

Are the range endpoints included?

Yes. The minimum and maximum are both eligible results when they match the selected precision and integer filter.

What does unique mean?

Unique means sampling without replacement. A value can appear at most once in that draw, so the range must contain at least as many eligible values as requested.

Why can a frequency chart look uneven?

Randomness does not force small samples to be balanced. Frequencies usually become more stable only across many independent draws.

Can I generate decimal values?

Yes. Decimal mode samples uniformly from the fixed increments created by your chosen number of decimal places.

Can I use the results in a spreadsheet?

Yes. Download a CSV file with one generated value per row, or copy all values and paste them into your spreadsheet.

Can I generate many values at once?

Yes. Choose any amount from 1 to 1,000. For very large samples, download the CSV or TXT result instead of copying individual values.

Are results stored?