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Random Number Generator

Generate random numbers, roll dice, or flip coins

Methodology & standardsRuns in your browser

Inputs

Results update live

Interpretation

How Random Number Generation works

The Random Number Generator uses JavaScript's Math.random() to produce pseudo-random numbers within your specified range. It also includes dice roller and coin flip modes for common randomization needs.

Example

Key features

A realistic scenario showing how the calculation guides a practical decision.

Formula

Random integer in [min, max]: Math.floor(Math.random() * (max - min + 1)) + min

  • Generate random numbers in any range
  • Generate multiple numbers at once (up to 1000)
  • Option to allow or prevent duplicates
  • Sort results ascending
  • Dice roller with d4, d6, d8, d10, d12, d20
  • Coin flip with heads/tails tally

Watch out

Common mistakes

  • When duplicates are disabled, the maximum count of numbers is limited to the range size. For cryptographic purposes, use window.crypto.getRandomValues() instead of Math.random().