Random Number Generator
Generate random numbers, roll dice, flip coins, and pick random items from a list.
About Random Number Generator
Random number generation is fundamental in computing, statistics, gaming, cryptography, and scientific simulations. This tool uses the Web Crypto API (window.crypto.getRandomValues), which provides cryptographically secure random numbers — the same standard used for security-sensitive applications like encryption key generation and secure token creation.
Cryptographically secure random number generators (CSPRNGs) differ from simple pseudo-random generators (like Math.random) in that their output is unpredictable and cannot be reproduced from the seed. This makes them suitable for applications where fairness and unpredictability are essential, such as lottery draws, random sampling for research, game mechanics, and password generation.
Features
Number Generator: Generate one or multiple random numbers within any range. Enable "unique" mode to prevent duplicates. Dice Roller: Roll 1-20 dice with 2-100 sides each. Perfect for tabletop RPGs like D&D. Coin Flip: Simulates a fair coin toss with running statistics. List Picker: Randomly select items from a custom list — great for making decisions, raffles, or random assignments.
FAQ
Q: Are the numbers truly random?
A: This tool uses the Web Crypto API, which provides cryptographically secure random numbers. While no computer can generate "true" random numbers (which require physical phenomena), CSPRNG output is indistinguishable from true randomness for all practical purposes.
Q: Can I use this for a lottery or raffle?
A: Yes. The cryptographic randomness ensures fair and unbiased selection. For official lotteries, however, dedicated certified random number systems are typically required by law.
Q: Is the dice roller fair?
A: Yes. Each die roll is independently generated using the crypto API, giving each face an equal probability. Over many rolls, the distribution will closely match the theoretical uniform distribution.
Q: Is my data safe?
A: Yes. All random generation happens locally in your browser. No data is sent to any server.