Top 10 Firefox extensions to avoid

Adblock and Adblock Plus

Obviously, we have some bias when it comes to ad-blocking extensions, as Computerworld is an ad-supported site. We also understand that these are very popular extensions. But if everyone blocked ads, how would sites such as ours continue to offer content free of charge?

We'll be the first to admit that there are some horribly annoying ads out there. (Buzzing bee, anyone?) But we prefer using Nuke Anything Enhanced to zap the annoying ads while continuing to support the sites we love by allowing most ads to appear.

PDF Download

Here's another extension that works as advertised and is very popular, but it seems like overkill for most users and can cause headaches for others. PDF Download lets you control how Firefox handles PDF files when you click on them -- you can display a pop-up box that lets you choose whether to download, open or view the file as HTML. You can also set it to take one of these actions by default, skipping the pop-up.

PDF Download's pop-up dialog.

Besides the option to view the file as HTML, the real draw for many people is the ability to have PDF files open in the external PDF viewer of their choice rather than the Adobe Reader plug-in for Firefox. Using the external viewer is significantly faster on some systems but not at all on others. Likewise, viewing as HTML sometimes takes longer than opening the PDF with the Adobe Reader plug-in.

So what's the problem? The extension can run into trouble when it tries to handle certain PDFs. Some Web sites send you to a "silent interstitial" page for tracking purposes or some other reason, then redirect you to the PDF. In these cases, the extension won't work. Usually when this happens, PDF Download just gets bypassed, but we've had Firefox freeze up when dealing with redirected PDFs, too. For the little benefit that PDF Download provides, the problems it can cause just aren't worth it.

VideoDownloader

Homegrown video is hot right now, and why not? Sites like YouTube and Google Video make it easy to put content online for Web denizens to enjoy. The VideoDownloader extension promises a way to download video from these sites and many more for your offline viewing pleasure. Sounds great, right?

The problem is that the extension has to connect to a Web site in order to work, and more often than not, you'll find that instead of a download window, what you get is "Service Temporarily Unavailable." When it does finally work, the download is infuriatingly slow.

What you should see when you try to download a video (left) ... and what you'll often see instead.

Perhaps the extension is a victim of its own success, but until the server issues are addressed, save yourself some aggravation and skip this one.