There are quite few test-bed online for your web-development . JSFiddle was on the top but now it is loosing its sheen. I have now moved most of my web-development tests to "plunker" which is much advanced than already available ones. Moreover you can integrate with your github.com id thus keeping version of your code
Please find a sample Plunker embedded into google blogger (Sample below)
Code to embed is:
Please find a sample Plunker embedded into google blogger (Sample below)
Code to embed is: