Here are Firefox Extensions that simplifies and contributes to a wholesome web designing experience.

Firebug

Need to edit CSS or Javascript live on any web page? Firebug is just the extension you should have in you web designer’s toolbox. You can have Firebug open in a separate window or conveniently placed at the bottom half of your browser. Firebug does a good job identifying errors relating to JavaScript, CSS, and XML.The extension also allows you to locate difficult-to-find HTML code and edit it live. Also thrown in are useful tools which allow you to debug Javascript and even execute Javascript on the fly.

YSlow

You have designed a wonderful web page. Problem is it loads pretty slowly. A slow-loading page is the bane of web designers. It’s a sure way to drive traffic away from your site. YSlow runs through your page and provides reasons for the sluggish loading. The extension also provides suggestions for improvements to speed up page loads if there are any. This tool, offered by Yahoo Developer Network, works only if Firebug is installed.

Colorzilla

Just spotted an interesting colour combination on a web page? Would like to reproduce it in the web page you’re designing? Colorzilla is the tool for you to easily acquire a colour reading. Usually if you want to get the hex code of a colour on a web page you would have to grab and sent it to your image editor to get the code. With Colorzilla integrated into your Firefox browser, you need only two clicks to get the code. Yes, the RGB values will be displayed as well.

Font Finder

If you see an eye-pleasing font on a webpage you’ll wonder what the font type is. More often than not you’ll have a hard time figuring it out. With Font Finder you highlight the text portion and with a right click of your mouse, you’ll be privy to information on font size, font family and also other CSS details.

Measureit

If you would like to quickly measure any area over a web page Measureit comes to your aid. This extension comes in handy especially when you want to know the measurements of the different areas on an impressive web page. All you have to do is highlight a desired area and the pixel width and height will be displayed.

SEO for Firefox

The download site claims that over 130, 000 webmasters use this extension to cover their SEO needs. It’s no surprise because the extension provides some valuable details.

Firstly, you get the Google PageRank, if any. You can also determine the age of a web page. Details of when a web page was first indexed by archive.org are provided. Another top feature is the estimate of the number of links pointing to a domain. As a web designer this tool will come in handy when you have to provide a client with important SEO details of a competitor website.