# number-is-nan [](https://travis-ci.org/sindresorhus/number-is-nan) > ES2015 [`Number.isNaN()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isNaN) [ponyfill](https://ponyfill.com) ## Install ``` $ npm install --save number-is-nan ``` ## Usage ```js var numberIsNan = require('number-is-nan'); numberIsNan(NaN); //=> true numberIsNan('unicorn'); //=> false ``` ## License MIT © [Sindre Sorhus](http://sindresorhus.com)