npm install --save detect-nodevarisNode=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:
module.exports=false;// Only Node.JS has a process variable that is of [[Class]] processtry{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.