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 Latest Draft (ECMA-262) The definition of 'Number.MAX_SAFE_INTEGER' in that specification. |
Draft |
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.
| Feature | Chrome | Firefox | Edge | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic Support | 34 | 31 | (Yes) | (No) | (Yes) | 9 |
| Feature | Android | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
|---|---|---|---|---|---|---|---|
| Basic Support | (Yes) | (Yes) | (Yes) | 31 | (No) | (Yes) | 9 |