ErrorZilla Mod is a free extension for Mozilla's Firefox Web browser that updates the domain access error page. It's basically the venerable ErrorZilla extension, only with the old logo replaced by the Firefox logo. It also sports a series of buttons accessing various DomainTools utilities for diagnosing what went wrong when Web sites don't load. It downloads and installs like any Firefox add-on; essentially automatically, with nothing to configure.
If a cop is never around when you need one, try finding a Web page that won't load. Fortunately, we hoard bookmarks, and we found one that refused to load in a few tries. After spinning its wheels for a while, Firefox showed the ErrorZilla Mod page with the usual "connection was reset" message, but with seven buttons added: Retry This, Ping, Google Cache, Trace, Coralize, Whois, and Wayback. Though we were fairly sure the Web site in question was long gone, we ran some tests anyway. Google Cache found nothing, but Trace opened TraceRoute and listed the server trail to the point that it timed out and was aborted. We had the best luck with the Internet Wayback Machine, which had archived page views for the site from... well, never mind how long ago it was. We were unable to open ErrorZilla Mod's tool links in a new tab or window from the error page, which would have speeded things up since we had to wait for our target page to fail to load every time we tried a tool and browsed back. Nevertheless, ErrorZilla Mod makes definite improvements to the Firefox error message page.
While finding a Web site that won't load isn't exactly easy or a productive use of your time, sooner or later you know you're going to hit an error message. When you do, you'll be able to appreciate ErrorZilla Mod and its ability to quickly access useful diagnostic tools.