This was first posted in my old, dead blog Jazzed Up! on Mar 24, 2008 1:44 PM

This article tells your how to download videos, not only from YouTube, but also from other video sharing sites using Firefox. I’ll be considering only YouTube here. The procedure will be the same for any streaming media.

Note (07 Jul, 2009): Though this is a very cool trick, right now, I personally use Internet Download Manager with it’s integrated browser add-ons for downloading embedded stuff (including flash, videos and audio).

Note for linux users: See this comment by Binny V A

Step 1: Go to YouTube and play the video you want to download.

Step 2: After the video has loaded, open a new tab (Ctrl + T) or a new Firefox window and type

about:cache

in the address bar.

Copy the location of the Cache Directory. (It’s different for everyone)

Screenshot:

Step 3: Open the Run dialog box (Start -> Run), paste the path of the Cache Directory (Ctrl + V), and press enter. You’ll now see a list of files with weird names

Step 4: Sort the files according to their size. The biggest file is most probably your video. Usually, the size of a 4-5 minute long video is around 10 MB.

Step 5: After you locate the largest file, copy it to some folder on your computer and give it an extension – .flv

You can play this using any player which supports FLV format. A good player is the Media Player Classic which is available with the K-Lite Codec Pack. You can also try FLV Player.

If you want to convert the flv to an avi file, you can download Free Flv to Avi Converter.

This trick can be applied to any video sharing site. The only thing is that you have to give the correct extension (In youtube, it’s .flv) to the file.

Cheers!