Question 1

How is the random number generated?

Accepted Answer

This tool uses crypto.getRandomValues, the Web Crypto API's CSPRNG (Cryptographically Secure Pseudo-Random Number Generator). It is seeded from hardware entropy sources (OS entropy pool) and is suitable for cryptographic applications — unlike Math.random(), which is not CSPRNG.

Question 2

What is the difference between Math.random() and crypto.getRandomValues?

Accepted Answer

Math.random() is a fast pseudo-random generator with no security guarantees — predictable if the seed or state is known. crypto.getRandomValues draws from a CSPRNG seeded with hardware entropy, making output cryptographically unpredictable. Always use the latter for security-sensitive values.

Question 3

What is modulo bias and does this tool have it?

Accepted Answer

Modulo bias occurs when a random range doesn't evenly divide the random source range, making some values slightly more likely. This tool uses rejection sampling to eliminate modulo bias, ensuring perfectly uniform distribution across any integer range you specify.

Générateur de nombres aléatoires

Entrée

Résultat

Questions fréquentes