### Install ```shell npm install --save detect-node ``` ### Usage: ```js var isNode = require('detect-node'); if (isNode) { console.log("Running under Node.JS"); } else { alert("Hello from browser (or whatever not-a-node env)"); } ``` The check is performed as: ```js module.exports = false; // Only Node.JS has a process variable that is of [[Class]] process try { module.exports = Object.prototype.toString.call(global.process) === '[object process]' } catch(e) {} ``` Thanks to Ingvar Stepanyan for the initial idea. This check is both **the most reliable I could find** and it does not use `process` env directly, which would cause browserify to include it into the build.