# decamelize [![Build Status](https://travis-ci.org/sindresorhus/decamelize.svg?branch=master)](https://travis-ci.org/sindresorhus/decamelize) > Convert a camelized string into a lowercased one with a custom separator > Example: `unicornRainbow` → `unicorn_rainbow` ## Install ```sh $ npm install --save decamelize ``` ## Usage ```js var decamelize = require('decamelize'); decamelize('unicornRainbow'); //=> unicorn_rainbow decamelize('unicornRainbow', '-'); //=> unicorn-rainbow ``` ## API ### decamelize(input, [separator]) #### input *Required* Type: `string` #### separator Type: `string` Default: `_` ## Related See [`camelcase`](https://github.com/sindresorhus/camelcase) for the inverse. ## License MIT © [Sindre Sorhus](http://sindresorhus.com)