# Math.random()

## Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The ** Math.random()** static method returns a floating-point, pseudo-random number that's greater than or equal to 0 and less than 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.

**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 `Crypto.getRandomValues()`

method.

## Try it

## Syntax

```
Math.random()
```

### Parameters

None.

### 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 reach 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) {
const minCeiled = Math.ceil(min);
const maxFloored = Math.floor(max);
return Math.floor(Math.random() * (maxFloored - minCeiled) + minCeiled); // 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) {
const minCeiled = Math.ceil(min);
const maxFloored = Math.floor(max);
return Math.floor(Math.random() * (maxFloored - minCeiled + 1) + minCeiled); // 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