If you're looking to Download JS Runner on your Chromebook laptop Then read the following guideline.

Write and run JavaScript/HTML code instantly! JS Runner is a handy tool for learning JavaScript/HTML or running JavaScript for daily tasks. * console.log() is now supported! Simply type JavaScript code and press "Command-R" to run it, that is all! You don't event need to save the file first! * Features • Type and run JavaScript/HTML code instantly • Syntax highlighting • Auto completion • Various themes * FAQ Q: What kind of JavaScript engine does JS Runner use? A: JS Runner uses the WebKit JavaScript engine and supports most web browser features.