I develop web applications and test them in Firefox, for Firefox provides many extensions that are not only useful, but sometimes vital to the completion of my projects. Over a period of time, I have been continuously evaluating different Firefox extensions in attempting to sort out the valuable ones (for web development). At last, I come up with these five.
Live HTTP Headers
This extension captures raw HTTP headers and displays both client request and server response. With this extension, you can easily examine headers such as server status code, Content-Encoding (to determine if compression is enabled), cookies, Content-Type, Etag, Expires and Cache-Control. If you need to optimize site performance by fine tuning browser caches, look no further, this is the tool for you. Download this extension.
YSlow provides a component view. In it you can view a list of external files which are associated with the current benchmarked page. For each file, you can inspect whether compression (usually in gzip) is enabled, expires date in the header is optimized, and Etag is presented. Download YSlow.
Its name already suggested that this is a tool for web developers. This extension combines various useful tools into one. Among them, you can always find something that can assist your web development. My favorite ones are Resize Window and Cookie tool. With Resize Window extension, you can test how well a page fits into different screen resolutions without having actually changing the screen resolution. Cookie tool allows you to view and edit cookies under current domain. There are numerous other features that Web Developer provides. Download and Explore them yourself.
Line Guides and Ruler in Web Developer extension
For testing purpose, web developers frequently need to perform repetitive tasks. An example scenario of such task is the testing of registration form. To ensure the form is functional, one needs to enter some garbage data before a test can be performed, and it needs to be redone upon the next test. This kind of repetition is inarguably annoying and the solution is iMacro.
iMacro is yet another mighty extension of Firefox. iMacro supports many kinds of browser automations. It can automatically fill out HTML forms, change browser URL, crawl information from web pages, simulate mouse click, and more. Download iMacro.
Here's a sample macro that fills out HTML form in iMacro:
TAG TYPE=INPUT:TEXT ATTR=NAME:email CONTENTemail@example.com
TAG TYPE=INPUT:PASSWORD ATTR=NAME:password CONTENT=111222
That is my list of Firefox extensions that I find the most useful to me. Hopefully they can become useful to you as well.