# Math.random()

The `Math.random()` function returns a floating-point, pseudo-random number in the range 0 to less than 1 (inclusive of 0, but not 1) with approximately uniform distribution over that range — which you can then scale to your desired range. The implementation selects the initial seed to the random number generation algorithm; it cannot be chosen or reset by the user.

## Try it

Note: `Math.random()` does not provide cryptographically secure random numbers. Do not use them for anything related to security. Use the Web Crypto API instead, and more precisely the `window.crypto.getRandomValues()` method.

## Syntax

``````Math.random()
``````

### Return value

A floating-point, pseudo-random number between `0` (inclusive) and 1 (exclusive).

## Examples

Note that as numbers in JavaScript are IEEE 754 floating point numbers with round-to-nearest-even behavior, the ranges claimed for the functions below (excluding the one for `Math.random()` itself) aren't exact. If extremely large bounds are chosen (2^53 or higher), it's possible in extremely rare cases to calculate the usually-excluded upper bound.

### Getting a random number between 0 (inclusive) and 1 (exclusive)

``````function getRandom() {
return Math.random();
}
``````

### Getting a random number between two values

This example returns a random number between the specified values. The returned value is no lower than (and may possibly equal) `min`, and is less than (and not equal) `max`.

``````function getRandomArbitrary(min, max) {
return Math.random() * (max - min) + min;
}
``````

### Getting a random integer between two values

This example returns a random integer between the specified values. The value is no lower than `min` (or the next integer greater than `min` if `min` isn't an integer), and is less than (but not equal to) `max`.

``````function getRandomInt(min, max) {
min = Math.ceil(min);
max = Math.floor(max);
return Math.floor(Math.random() * (max - min) + min); //The maximum is exclusive and the minimum is inclusive
}
``````

Note: It might be tempting to use `Math.round()` to accomplish that, but doing so would cause your random numbers to follow a non-uniform distribution, which may not be acceptable for your needs.

### Getting a random integer between two values, inclusive

While the `getRandomInt()` function above is inclusive at the minimum, it's exclusive at the maximum. What if you need the results to be inclusive at both the minimum and the maximum? The `getRandomIntInclusive()` function below accomplishes that.

``````function getRandomIntInclusive(min, max) {
min = Math.ceil(min);
max = Math.floor(max);
return Math.floor(Math.random() * (max - min + 1) + min); //The maximum is inclusive and the minimum is inclusive
}
``````

## Specifications

Specification
ECMAScript Language Specification
# sec-math.random

## Browser compatibility

BCD tables only load in the browser