Flems is a playground for web development. It's ideal for prototyping ideas & sharing working front-end code examples.


CodePen is described as 'A communal platform for front-end development offering real-time previews, project building, and showcases, enhancing skills through challenges' and is a very popular Code Editor in the development category. There are more than 50 alternatives to CodePen, not only websites but also apps for a variety of platforms, including Self-Hosted, Linux, Mac and Windows apps. The best CodePen alternative is jsFiddle, which is free. Other great sites and apps similar to CodePen are Replit, Firebase Studio, Qoder IDE and CodeSandbox.
Flems is a playground for web development. It's ideal for prototyping ideas & sharing working front-end code examples.


goormIDE is a powerful cloud IDE service to maximize the productivity for developers and teams. You can build your own development environment with just a few clicks and collaborate in real-time on the same docker container.




kodeWeave is a realtime coding playground for HTML, CSS and Javascript. Similar to JSFiddle and JSBin, but kodeWeave was made to work offline but also as a prototyping application to build applications for desktop operating systems while on mobile devices.




Plunker is an online community for creating, collaborating on and sharing your web development ideas.

Fastpen is an open source alternative to codepen that just stores the source code compressed, in the url.







Storm is an online web development environment which allows users to run HTML, CSS, Javascript code in real time in a secured environment. It supports sharing Scribble (Storm project) via a dedicated link and also allows users to use jQuery and React framework of JavaScript.

Codewith.it is an online HTML, CSS and JavaScript code playground with realtime preview with many tools for developing web pages and advanced code analysis systems, with many assistance tools.



Make Awesome Web Things, Demos, Apps with html, css, javascript in online code editor.


Codiad is an open source, web-based, cloud IDE and code editor with minimal footprint and requirements

Doesn't support preprocessors nor libraries