Ajax and javascript is hard to debug and find where it go wrong. One of the great offline tools to debug your ajax and javascript code is Firebug with Firefly extension. But you need to modify your code and insert some debug code from firebug, and you can see the result in Firebug windows. I have it in my Firefox browser to develop my projects, but sometimes i need to testing ajax live or testing javascript live without using Firebug.
These are the best 2 online ajax and javascript testing tools, they have already include some ajax library such as jquery, prototype, YUI, mootools, dojo, etc.. And we can use it for free! It helped so much during my development time, since i can lively testing my jquery code, and see where the things go wrong, and after it is good, just copy and paste to my development server back and continue.
1. JSBin
JS Bin is an open source collaborative JavaScript debugging tool. It have nice and clean user interface. And you can save your code and share it to your co-worker or anyone and ask where you go wrong. Usually asking someone else to help you will solve your problem, because they can see what you couldn’t.
2. JSFiddle
[quote]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 build 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.[/quote] JSFiddle still in alpha development, it have more complex feature than JSBin such us membership and HTML tidyup (i like this feature). You can also put your HTML, CSS and javascript code in the separate box 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 light and neat. So i could concentrate more to my code.
Have you try use one of them? They worth to try and i like to support them by publishing this article. if you have other nice tools please feel free to leave any comment below.