Once you have installed the extension, you can access it from Tools menu or using the shortcut F12 or by clicking on the bug icon in the status bar of Firefox (Ctrl + F12 to open in a new window). Since it consumes considerable amount of resources and slows down the browser, you can disable it during normal browsing by right-clicking on the icon and clicking on suspend. You can also add specific sites to Firebug from theConsole menu. It is because of this reason that the console panel is disabled by default, you can also disable Script and Net panels if you find the performance susbtantially degraded. However, assuming that everything goes on fine let us explore the features of Firebug and how it can assist in Web development.
For instance :
console.log(“%s is an extensionof %d”, “Firebug”, “Firefox”);
Firebug is an extension of Firefox
HTML Tab shows the HTML code as an indented heirarchy of DOM nodes.
CSS Tab displays the stylesheets loaded at the point in time.
DOM Tab displays all the page objects and properties.
This was a basic overview of Firebug aiming to help you get started if you have not already. Once you have started using it, you will find that this tiny add-on has all the functionalities that you would ever need to help you develop or test your web application.