Random Number Generator

Generate cryptographically secure random integers in any range. Single or bulk.

100% in your browser · No uploads

What this does

Random Number Generator produces cryptographically secure random integers in any range. Generate a single number or up to 10,000 at once, with optional 'no duplicates' mode for raffles and sampling.

When to use it

  • Picking a winner from a list of entrants
  • Generating sample data for testing
  • Random sampling from a numbered list (e.g. survey respondents)
  • Replacing Math.random() with secure randomness for raffles or contests

Frequently asked

How is this different from Math.random()?

Math.random() is pseudo-random and predictable to determined attackers. This tool uses crypto.getRandomValues, the same source browsers use for HTTPS — it's unpredictable even to someone watching every previous output.

How does 'no duplicates' work?

It generates a shuffled list of every integer in the range and returns the first N. Works perfectly as long as N ≤ range size.