Web/JavaScript/Reference/Global objects/Number/EPSILON

The Number.EPSILON property represents the difference between 1 and the smallest floating point number greater than 1.

You do not have to create a Number object to access this static property (use Number.EPSILON).

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

Property attributes of Number.EPSILON
Writable	no
Enumerable	no
Configurable	no

Description

The EPSILON property has a value of approximately 2.2204460492503130808472633361816E-16, or 2-52.

Examples

Testing equality

x = 0.2;
y = 0.3;
z = 0.1;
equal = (Math.abs(x - y + z) < Number.EPSILON);

Polyfill

if (Number.EPSILON === undefined) {
    Number.EPSILON = Math.pow(2, -52);
}

Specifications

Specification
ECMAScript (ECMA-262)The definition of 'Number.EPSILON' in that specification.

Browser compatibility

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
EPSILON	Chrome Full support 34	Edge Full support 12	Firefox Full support 25	IE No support No	Opera Full support 21	Safari Full support 9	WebView Android Full support ≤37	Chrome Android Full support 34	Firefox Android Full support 25	Opera Android Full support 21	Safari iOS Full support 9	Samsung Internet Android Full support 2.0	nodejs Full support 0.12

Legend

Full support  

Full support

No support  

No support

See also

• The Number object it belongs to

Number.EPSILON by Mozilla Contributors is licensed under CC-BY-SA 2.5.