JSOM Fiddle

JSOM Fiddle allows you to prototype your JSOM client scripts directly on the SharePoint site.

Includes a fully featured JavaScript editor with syntax and error highlighting.

Lots of sample code included to get your testing underway.

Save your scripts so that you can come back to them again and again. The scripts can be exported and imported to other sites so you can have all your favourite snippets in one place.

Note: JSOM Fiddle only supports IE9 and above