Have you ever been lost trying to find a particular piece of code within a style sheet or html file? Stop playing the hunter, and download Firebug and increase your productivity.
Firebug integrates with Firefox to put a wealth of web development tools at your fingertips while you browse. You can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page.

When things go wrong, Firebug lets you know immediately and gives you detailed and useful information about errors in JavaScript, CSS, and XML.

Firebug makes it simple to find HTML elements buried deep in the page. Once you’ve found what you’re looking for, Firebug gives you a wealth of information, and lets you edit the HTML live.

Firebug’s CSS tabs tell you everything you need to know about the styles in your web pages, and if you don’t like what it’s telling you, you can make changes and see them take effect instantly.

The F12 key is undoubtedly the fastest way to get to Firebug. Train yourself to hit that key when it’s time to go debugging. If you’re the big screen type, use Control+F12 (or Command+F12 on Mac) to open Firebug in a separate window.

Download Firebug here.