Ajax and JavaScript is hard to debug and find where it goes wrong. One of the great offline tools to debug your Ajax and JavaScript code is Firebug with the Firefly extension. But you need to modify your code and insert some debug code from Firebug, and you can see the result in the Firebug window. I have it in my Firefox browser to develop my projects, but sometimes I need to test Ajax live or test JavaScript live without using Firebug.
These are the best 2 online Ajax and JavaScript testing tools. They already include some Ajax libraries such as jQuery, Prototype, YUI, MooTools, Dojo, etc. And we can use them for free! They helped so much during my development time, since I can live-test my jQuery code, see where things go wrong, and after it looks good, just copy and paste back to my development server and continue.
1. JSBin
JS Bin is an open source collaborative JavaScript debugging tool. It has a nice and clean user interface. You can save your code and share it with a co-worker or anyone and ask where you went wrong. Usually asking someone else to help will solve your problem, because they can see what you couldn’t.
2. JSFiddle
JsFiddle is a playground for web developers, a tool which may be used in many ways. One can use it as an online editor for snippets built from HTML, CSS and JavaScript. The code can then be shared with others, embedded on a blog, etc. Using this approach, JavaScript developers can very easily isolate bugs. We aim to support all actively developed frameworks — it helps with testing compatibility.
JSFiddle is still in alpha development. It has more complex features than JSBin such as membership and HTML tidy-up (I like this feature). You can also put your HTML, CSS and JavaScript code in separate boxes and run it to see the result.
I like to use them both during my development time, but I use JSBin more often since it is light and neat, so I can concentrate more on my code.
Have you tried one of them? They are worth trying and I like to support them by publishing this article. If you have other nice tools please feel free to leave a comment below.