Number.MIN_SAFE_INTEGER

Try it

const x = Number.MIN_SAFE_INTEGER - 1;
const y = Number.MIN_SAFE_INTEGER - 2;

console.log(Number.MIN_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 about -9 quadrillion).

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 correctly compare them. For example, Number.MIN_SAFE_INTEGER - 1 === Number.MIN_SAFE_INTEGER - 2 will evaluate to true, which is mathematically incorrect. See Number.isSafeInteger() for more information.

As mentioned in Number.EPSILON, the precision of numbers depends on their magnitude. Number.MIN_SAFE_INTEGER represents the smallest value at which integer-level operations can be performed precisely, but you can still perform meaningful arithmetic on numbers more negative than that, just without integer-level precision. The largest representable number in JavaScript is actually Number.MAX_VALUE, which is approximately 1.7976931348623157 × 10³⁰⁸.

Because MIN_SAFE_INTEGER is a static property of Number, you always use it as Number.MIN_SAFE_INTEGER, rather than as a property of a number value.

Examples

Using MIN_SAFE_INTEGER

Number.MIN_SAFE_INTEGER; // -9007199254740991
-(2 ** 53 - 1); // -9007199254740991

Specifications

Browser compatibility

See also

• Polyfill of Number.MIN_SAFE_INTEGER in core-js
• es-shims polyfill of Number.MIN_SAFE_INTEGER
• Number.MAX_SAFE_INTEGER
• Number.isSafeInteger()
• BigInt