Number.isFinite()
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.
TheNumber.isFinite() static method determines whether the passed value is a finite number — that is, it checks that a given value is a number, and the number is neither positiveInfinity, negativeInfinity, norNaN.
Try it
console.log(Number.isFinite(1 / 0));// Expected output: falseconsole.log(Number.isFinite(10 / 5));// Expected output: trueconsole.log(Number.isFinite(0 / 0));// Expected output: falseSyntax
js
Number.isFinite(value)Parameters
valueThe value to be tested for finiteness.
Return value
The boolean valuetrue if the given value is a finite number. Otherwisefalse.
Examples
Using isFinite()
js
Number.isFinite(Infinity); // falseNumber.isFinite(NaN); // falseNumber.isFinite(-Infinity); // falseNumber.isFinite(0); // trueNumber.isFinite(2e64); // trueDifference between Number.isFinite() and global isFinite()
In comparison to the globalisFinite() function, this method doesn't first convert the parameter to a number. This means only values of the type numberand are finite returntrue, and non-numbers always returnfalse.
js
isFinite("0"); // true; coerced to number 0Number.isFinite("0"); // falseisFinite(null); // true; coerced to number 0Number.isFinite(null); // falseSpecifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-number.isfinite |