Number.MAX_SAFE_INTEGER

{{JSRef}}

The Number.MAX_SAFE_INTEGER static data property represents the maximum safe integer in JavaScript (2⁵³ – 1).

For larger integers, consider using {{jsxref("BigInt")}} .

{{InteractiveExample("JavaScript Demo: Number.MAX_SAFE_INTEGER")}}

const x = Number.MAX_SAFE_INTEGER + 1;
const y = Number.MAX_SAFE_INTEGER + 2;

console.log(Number.MAX_SAFE_INTEGER);
// Expected output: 9007199254740991

console.log(x);
// Expected output: 9007199254740992

console.log(x === y);
// Expected output: true

Value

9007199254740991 (9,007,199,254,740,991, or ~9 quadrillion).

{{js_property_attributes(0, 0, 0)}}

Description

Double precision floating point format only has 52 bits to represent the mantissa, so it can only safely represent integers between -(2⁵³ – 1) and 2⁵³ – 1. “Safe” in this context refers to the ability to represent integers exactly and to compare them correctly. For example, Number.MAX_SAFE_INTEGER + 1 === Number.MAX_SAFE_INTEGER + 2 will evaluate to true, which is mathematically incorrect. See {{jsxref("Number.isSafeInteger()")}} for more information.

Because MAX_SAFE_INTEGER is a static property of {{jsxref("Number")}} , you always use it as Number.MAX_SAFE_INTEGER, rather than as a property of a number value.

Examples

Return value of MAX_SAFE_INTEGER

Number.MAX_SAFE_INTEGER; // 9007199254740991

Relationship between MAX_SAFE_INTEGER and EPSILON

{{jsxref("Number.EPSILON")}} is 2^-52, while MAX_SAFE_INTEGER is 2⁵³ – 1 — both of them are derived from the width of the mantissa, which is 53 bits (with the highest bit always being 1). Multiplying them will give a value very close — but not equal — to 2.

Number.MAX_SAFE_INTEGER * Number.EPSILON; // 1.9999999999999998

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

docs.rodeo

MDN Web Docs mirror