Firefox is one of the best tool available for web developers which equips the developer with code testing and debugging capabilities.
There are many useful firefox options and extensions that comes in handy during software development life cycle and in this article we will be listing few of useful plugins that we commonly use.
To find information related to the page that is getting displayed on the browser click Tools > Page info. This will give you permission settings of a page, security identity of the page, feed url and other page specific information like page content-type, encoding, meta tags used, cookie permission settings etc.
Web Developer extension
Added as a toolbar in firefox, this extension gives CSS related information, page information, outlines page elements, tab index, gives topographic information and many such details.
Finds elements on the page corresponding to a given color, find out CSS rules and helps in checking the DOM element colors.
Helps give comprehensive list of CSS values for any chosen element.
If you are building applications which will involve heavy cross linking between pages this tool will gracefully point out the broken links in the pages helping the developers in swiftly modifying the links.
It comes handy for the designers especially when they want to find out the width/height of an image or the size of the layout as it draws a ruler to get the pixel dimensions.
Tool to find the http header information including the cookie information that is transmitted when a request for a page is made.
User Agent Switcher
As a developer have you ever come across a situation where you wanted to identify your web pages with different user agents IE6, IE7, Firefox to the web server. Then this is the tool that you are looking for. It also supports Flock, Seamonkey, Mac OS and Linux user agents.
IE TabFor cross browser compatibility especially with the varied CSS rules in different IE versions, it often becomes hectic to test the functionality across different browsers. This tool helps run IE as a tab inside firefox.
This is a plugin from yahoo and it aids in finding why a page loads slowly.