Generate random numbers between any range. Choose integers or decimals, generate up to 100 numbers at once, and copy all results.
Random Number Generator
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What Is a Random Number Generator?
A random number generator (RNG) produces numbers that cannot be reasonably predicted in advance. Our tool uses your browser's built-in Math.random() function — a pseudo-random number generator (PRNG) that is fast, uniform, and suitable for most everyday uses.
Pseudo-Random vs. True Random
Pseudo-random generators use a mathematical algorithm seeded with a starting value (often the current time). They produce sequences that appear random but are technically deterministic. Browser Math.random() is pseudo-random and is not suitable for cryptography or gambling systems.
True random generators derive randomness from physical phenomena — atmospheric noise, radioactive decay, or thermal noise. Services like random.org use atmospheric noise. For most everyday applications (picking lottery numbers by hand, game decisions, random sampling), a pseudo-random generator is indistinguishable from true random.
Common Uses for Random Number Generators
Picking raffle or lottery winners fairly
Randomizing order (who presents first, who picks first)
Statistical sampling from a population
Game design: dice rolls, card shuffles, loot drops
Math.random() produces numbers from a uniform distribution — every number in the range is equally likely. This is correct for most purposes. Some use cases need different distributions (normal/bell-curve, exponential, Poisson) which require additional transformation.
Frequently Asked Questions
It uses your browser's Math.random() function, which is a cryptographically non-secure pseudo-random number generator (PRNG). The output is uniformly distributed and effectively unpredictable for everyday purposes — picking winners, games, sampling — but should not be used for security, cryptography, or gambling systems.
Number your entries (1, 2, 3...), set the Min to 1, Max to the total number of entries, and generate 1 random number. The result is your winner's number. For multiple winners without repeats, check 'No duplicates' and generate multiple numbers.
JavaScript numbers handle integers precisely up to 2^53 - 1 (about 9 quadrillion). For practical purposes, any range you would normally need (up to billions) works fine. Very large ranges may have slight rounding at the edge values for decimal modes.
Yes — check the 'No duplicates' option before generating. This ensures each number in the output appears only once. Note that this only works for integers when the count doesn't exceed the range size.