Often times I find myself wanting to run a bit of JavaScript code to check if it’s working properly. I do this with my notes or when I’m trying to understand something I’ve read online.

Typically, I would use the console on my browser, but that has its limitations. There are also online tools like JSFiddle, CodePen, and Replit. However, these tools tend to be geared towards frontend development with HTML and CSS, and some even require you to login just to use their service.

I found a better solution is to use RunJS. It supports both JavaScript and TypeScript, has access to both Node.js and Web APIs, and generates live feedback as you type. Being a desktop application it’s also a lot faster to access then an online tool.

RunJS works on Linux, Mac, and Windows. On macOS, install with Homebrew,

brew install --cask runjs