Firebug extensions are a sort of meta-extension that lets you add on to Firebug. Developers are adding some features that we’re starting to find hard to live without.
Here we’ll lay out our five faves.
We’ve written about YSlow before. It measures your site’s speed against Yahoo’s rules for high-performance websites. It generates a little report card that analyzes your page’s events and components, pointing out which pieces of the page are causing the most problems.
It’s worth a glimpse into YSlow from time to time, even if you feel like your site is performing well. You may still find improvements to make, and if not, at least you’ll pat yourself on the back with your good score.
Firecookie shows all the cookies being accessed by the current web page. You can see when one has been changed, and you can alter your cookie settings for accepting or denying cookies right from the Firebug panel.
I like the cookie access in Firefox 3′s new Page Info screen, but pairing cookies with Firebug just makes sense. One of the best things about Firebug extensions is that they can bring all your debugging to one place.
Speaking of bringing all your debugging to one place, I never would have imagined I needed FirePHP, but now I love it. It brings PHP debugging into Firebug using special “X-FirePHP-Data” headers that are invisible in the browser. FirePHP requires a PHP library to send the debugging messages.
There’s a similar extension for Cold Fusion called ColdFire. We haven’t tried it, and they aren’t listed on the Firefox extension site, so proceed with caution.
Really, there’s no need to have a different extension for each programming language. I’d rather see a standard, language-agnostic version. Then, any language could send header data to Firebug.
4. Pixel Perfect
Okay designers, this one’s for you. Pixel Perfect helps you create designs that are just right. You can overlap a partially transparent mockup above your actual web page. Then use Firebug’s standard CSS controls to find just the right settings to make the design pixel-perfect.
First a warning: Some people have experienced problems with Firebug when using this extension. It’s worked fine for me.