Number.MAX_SAFE_INTEGER

The Number.MAX_SAFE_INTEGER constant represents the maximum safe integer in JavaScript (253 - 1).

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

Description

The MAX_SAFE_INTEGER constant has a value of 9007199254740991. The reasoning behind that number is that JavaScript uses double-precision floating-point format numbers as specified in IEEE 754 and can only safely represent numbers between -(253 - 1) and 253 - 1.

Safe in this context refers to the ability to represent integers exactly and to correctly compare them. For example, Number.MAX_SAFE_INTEGER + 1 === Number.MAX_SAFE_INTEGER + 2 will evaluate to true, which is mathematically incorrect. See Number.isSafeInteger() for more information.

Because MAX_SAFE_INTEGER is a static property of Number, you always use it as Number.MAX_SAFE_INTEGER, rather than as a property of a Number object you created.

Examples

Number.MAX_SAFE_INTEGER // 9007199254740991
Math.pow(2, 53) - 1     // 9007199254740991

Specifications

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

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 34 31 (31) No support (Yes) 9
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) 32.0 (32) No support No support 9

See also

Document Tags and Contributors

 Contributors to this page: fleurdeswift, fscholz, aressler38, magwo, Mingun, realityking, Nevallem
 Last updated by: fleurdeswift,