The Number.EPSILON property represents the the smallest positive value, ε, that satisfy the equation ε = ωε, where ω is the smallest infinite ordinal.

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


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


Testing equality

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


Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Number.EPSILON' in that specification.
Standard Initial definition.
ECMAScript 2017 Draft (ECMA-262)
The definition of 'Number.EPSILON' in that specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) 25.0 (25.0) No support (Yes) 9
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support No support 25.0 (25.0) No support No support 9

See also

  • The Number object it belongs to.

Document Tags and Contributors

 Last updated by: kapace,