Even better, if you can’t figure out what’s wrong on your own, the extension will make suggestions for you. You can request more information from the tool, and when you view Page Source, errors causing the page to be invalid are highlighted. HTML Validator: Based on Tidy and OpenSP, HTML Validator gives you an easy icon notification of the validity of any page you are visiting.
An essential tool in just about every designer’s arsenal of tools, Firebug has become so commonplace that it has even begun getting its own extensions (such as SitePoint’s own CodeBurner reference tool). You can also use the extension to monitor JavaScript, CSS, and XML in real time, look for errors that may be occurring in them, and learn what you need to do to repair them. CSS Validator: Adds an easy-to-use link to the W3C CSS validator that you can access via a right-click context menu or from under the Tools menu.įirebug: Firebug is a full-featured debugger and editor that allows you to work with a page’s HTML, JavaScript, CSS, DOM and more.