1. JSFiddle

    Test your JavaScript, CSS, HTML or CoffeeScript online with JSFiddle code editor.

  2. repl.it

    Online Interpreters in JavaScript. Online coding and REPL. Run and share code.

  3. CodePen

    A front end web development playground.

  4. Plunker

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

  5. JS Bin

    Sample of the bin:

  6. Pastebin.com

    Pastebin.com is a website where you can store text for a certain period of time.

  7. kodeWeave

    HTML/CSS/JS and Markdown Code Playground For Web Designers and Developers

  8. Coding Ground

    Compileonline is now renamed to Coding Ground

  9. Dabblet

    dabblet is an interactive playground for quickly testing snippets of CSS and HTML code.

  10. Liveweave

    Liveweave is a HTML5, CSS3 & JavaScript playground for web designers and developers

  11. Thimble by Mozilla

    Webmaker - teach your self to code for the web.

  12. CodeSandbox

    Online playground for React