jsFiddle is the perfect solution; it provides a custom environment (based on user selections) to test (or fiddle with) your JavaScript, HTML, and CSS code right inside your browser. A quick tour ...

Even with something like React, there’s a certain amount of boilerplate code that shuffles information ... the powerful trio of HTML, JavaScript, and CSS, which continues to win out in the ...

The new release brings improvements to JavaScript heap profiles, CSS code formatting ... the semantic highlighting of JavaScript source in HTML files with what is seen in normal .jscode files.