Although there are many many FireFox extensions out there, only a small handful have proven useful, especially for a developer like me. So, here I give you a short and sweet list of the most useful FireFox extensions for designers and developers.
Web Developer Toolbar
I love this little tool. It simply displays the what type of server the website is running. It’s very useful if you are talking with a client and want to impress them really quickly: “Well, it looks like you’re running [INSERT SERVER HERE AND VERSION].”
Although I don’t use this is much as I probably should, it can be very useful at times. It allows you to drag a box on the screen, and displays it’s width in pixels.
This may be more useful to some designers, but when you need to fish out some colors from another site, or just need to double check some colors, this tool proves itself to be the cat’s pyjamas. You can grab the colors many different formats of RGB, and also HEX.