JS: Format Number

By Xah Lee. Date: 2015-03-06. Last updated: 2026-07-17.

JavaScript does not have a “format” or “printf” function. The following code are solutions.

Format with separator, money, metrix prefix, percentage, etc.

JS: Number .prototype .toLocaleString

To string, n decimal places

JS: Number.prototype.toFixed

To string, n significant digits

JS: Number.prototype.toPrecision

To string, scientific notation

JS: Number.prototype.toExponential

String Template

JS: Template String

Number to String, hexadecimal, binary

JS: Number.prototype.toString (Number to String)