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).

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 Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Number.EPSILON' in that specification.
Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
The definition of 'Number.EPSILON' in that specification.
Draft  

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung InternetNode.js
Basic supportChrome Full support YesEdge Full support YesFirefox Full support 25IE No support NoOpera Full support YesSafari Full support 9WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 25Opera Android Full support YesSafari iOS Full support 9Samsung Internet Android Full support Yesnodejs Full support 0.12

Legend

Full support  
Full support
No support  
No support

See also

  • The Number object it belongs to.

Document Tags and Contributors

Last updated by: snek,