Intl.NumberFormat.prototype.formatToParts() is scheduled to be added to the ECMAScript Internationalization API specification (Ecma 402). It adds a method to format a number to a list of tokens and their types (e.g. minusSign, integer, decimal, fraction, currency, percentSign, etc). See also the corresponding DateTimeFormat feature here: https://www.chromestatus.com/feature/6319456309477376
Docs: https://github.com/tc39/ecma402/files/41759/formatToParts.pdf https://github.com/zbraniecki/proposal-intl-formatToParts https://github.com/tc39/ecma402/issues/30