Prototype and explore your ideas with RunKit. RunKit notebooks completely remove the friction of trying new ideas. With one click you'll have a sandboxed JavaScript environment where you can instantly switch node versions, use every npm module without having to wait to install it, and even visualize your results. No more configuration, just straight to coding. The Global Library at Your Fingertips RunKit removes all barriers to finding existing libraries that already do what you need. In fact, you can even require multiple versions of the same package side by side in a document, providing unique debugging opportunities. Next Generation Time Traveling. RunKit takes time traveling debugging further using a revolutionary new technology called CRIU, which allows notebooks to snapshot the entire environment. That means you can rewind subprocesses, the filesystem, really just about anything in your session. Instant API. Create an API without worrying about servers or configuration. Just export a endpoint function and your notebook automatically becomes an HTTPS endpoint, accessible from any app. Great for prototyping iOS and Android backends, or creating microservices. Bring your code to life. RunKit makes it easy to let your users run the sample code in your blog posts and documentation right on your website.