This Mozilla add-on substitutes the traditional JavaScript Console with a more advanced Error Console.
One of Console 2's main features is its ability to filter errors based on type, language, and context. Users can choose to display errors that fall into the following categories: Errors, Warnings, and Messages. They can also filter by language, selecting between JavaScript, CSS, XML, and more. Furthermore, Console 2 provides context filters, allowing users to choose to view errors in either the Chrome or Content contexts.
In addition to its powerful filtering capabilities, Console 2 also includes several other features that enhance its functionality. These include a search box similar to the one found in the History and Bookmarks sidebars, the ability to hide duplicates, sidebar optimizations, customization of the toolbar, and accessibility improvements, among others.
Overall, Console 2 is a valuable upgrade to the JavaScript Console, offering powerful error filtering, a customizable interface, and improved accessibility. If you often use the JavaScript Console for debugging, Console 2 is definitely worth checking out.