General
Random Number Generator
Generate cryptographically secure random numbers, lottery picks, dice rolls, coin flips, and shuffled lists — all powered by crypto.getRandomValues().
Click Generate to get random numbers
How is this calculated?
Uses crypto.getRandomValues() for cryptographic randomness
Range: min + (random_uint32 % (max - min + 1))
Rejection sampling ensures uniform distribution
Shuffle: Fisher-Yates algorithm with crypto-random swaps
Coin: single random bit per flipFAQ
Frequently asked questions
How does this random number generator work?
It uses the Web Crypto API (crypto.getRandomValues) which provides cryptographically secure pseudo-random numbers. This is far more random than Math.random() and suitable for security-sensitive applications.
Can I generate lottery numbers?
Yes! Use the Lottery tab with presets for Powerball (5 numbers 1-69 + powerball 1-26), Mega Millions (5 numbers 1-70 + mega ball 1-25), and UK Lotto (6 numbers 1-59). Numbers are guaranteed unique.
Is the random number truly random?
crypto.getRandomValues() uses your operating system entropy source, making it cryptographically secure. It is suitable for generating keys, tokens, and lottery-style draws where unpredictability matters.
Can I roll multiple dice at once?
Yes! The Dice tab lets you roll 1-100 dice with customizable sides (4, 6, 8, 10, 12, 20, or custom). See individual results plus the total sum.
How does the list shuffler work?
Enter items separated by commas or newlines. The shuffler uses the Fisher-Yates algorithm with crypto-random swaps to produce an unbiased permutation of your list.
Is this random number generator free?
Yes, completely free with no sign-up required. All generation runs in your browser — no data is sent to any server and nothing is stored.