Have you ever wanted to “save” a video from YouTube, so that you can play it back anytime you want, even when you’re not connected to the internet?

There are numerous programs out there that supposedly let you do this, but they all look very suspicious (as in spyware-ish), so I decided not to bother with any of them. Instead, I figured out a quick way of saving YouTube videos the manual way:

• When your Internet browser views a web page, it stores most of the page’s content in a “cache” folder on your hard drive, so that the page loads faster the next time you go to it. This includes pictures, script files, and videos. So, technically, when you view a YouTube video, it’s already saved on your hard drive! The important step is to find the video in your cache folder.
• If you’re using Internet Explorer, the cache folder should be located at “C:\Documents and Settings\yourname\Local Settings\Temporary Internet Files“, where yourname is your Windows login name.
  If you’re using Firefox, the cache folder should be located at “C:\Documents and Settings\yourname\Local Settings\Application Data\Mozilla\Firefox\Profiles\default\Cache“.
• It’s a bit complicated to actually find the video you want in the cache folder, since neither Internet Explorer and Firefox give cached items proper file extensions. The best you can do here is sort the files by size, and look for files of a video-worthy size (several megabytes). Under Firefox, the files named _CACHE_nnn_ are special files, and not videos. A good method of doing this would be to clear your browser’s cache, then go to YouTube, view the video you want (and only that video), then go to the cache folder: the largest file in the cache should be the video. Now copy it out of the cache folder and rename it with a “.flv” extension, and you’ve got it!
• Now, to play back the saved FLV files is the remaining road block. Windows Media Player will not play these videos; neither will QuickTime, or Real Player. The best solution I’ve found is to use FLV Player, which is a small standalone utility just for playing FLV files.

  Update: The popular VideoLAN player now supports FLV videos natively, so a standalone player is no longer necessary.