When comparing JSFiddle vs Codepen, the Slant community recommends JSFiddle for most people. In the question“What are the best cloud IDEs?” JSFiddle is ranked 5th while Codepen is ranked 22nd. The most important reason people chose JSFiddle is:
Ranked in these QuestionsQuestion Ranking
Pro CoffeeScript and SCSS support
Pro Allows collaborating on code
JSFiddle makes it easy to save the code snippets and send the link to others who can view and edit the code.
Pro Supports a wide variety of frameworks and extensions
JSFiddle can switch to selection of frameworks and extensions including jQuery, AngularJS, ReactiveJS, D3 simply from a dropdown.
Pro Easily export your pen
CodePen makes it really easy to export code as a zip or Github Gist.
Pro Real time output
Pro Lots of support for frameworks and preprocessors
CodePen has an impressive amount of support for preprocessors (such as Jade, Haml, Slim, Sass, Less, Stylus, Coffeescript and PostCSS). There is also plenty of frameworks and libraries to pick from (Foundation, Bootstrap, Angular, D3, Backbone, Ember etc.).
Pro Great display/profile page
The codepen profile page allows you to display all of your public pens, and control which order you want them to be viewed in. This is great for showing off your work to possible employers, other devs etc..
Pro Easily fork pens
To fork a pen only requires clicking one button, and you'll be able to modify the pen on your own account.
Pro Great community pens
You can search through other pens, either by keyword or popular, picked or recent.
Con Not actually an IDE
JSFiddle is not actually an IDE and is only suitable for small blocks of code.