Online JavaScript Playground

Write and run code with instant live feedback.

Take Your Coding Offline – Download RunJS Desktop for Free.

The same great experience but with more 💪

Other platforms

Latest version: 3.0.3

macOS (.app) Universal
Windows (.exe) x64
Linux (.AppImage) x64 Arm64
Linux (.deb) x64 Arm64

Feature Comparison

OnlineDesktop
Run JavaScript and TypeScript
Autocomplete
NPM Packages
Type Checking
Node.js Integration
Hover Info
Snippets
AI Assistant
Multiple Tabs
Environment Variable Manager

What people are saying

RunJS is a fantastic app for quick sanity checking and prototyping. I like it because I dont have to mash the up arrow a bunch of times to get to set up my testing state like I would in dev tools, and I like that it evaluates continuously unlike a simple node script.
Len Woodward
Len WoodwardFull-Stack Web Developer
If you dreamt about a lightweight JS editor to run code immediately as you type and the browser console isn't quite handy, I'd recommend this one, nice tool for sketching fast and working locally on your computer (so you can do some sketching offline)
Sergey Panarin
Sergey PanarinSoftware Engineer