iTunes does a great job of managing music files on your iOS device, but adding video files to your iTunes library is a little more difficult. Oftentimes, a video file simply won't play in iTunes. The problem usually lies in the video file format; iTunes only supports a few video formats. But the free converter will help you import any video to iTunes.
Steps
Method 1 of 2: Prepare the video

Step 1. Determine the video file format that you want to add to iTunes
iTunes only supports the following video formats: .mov, .m4v, .mp4.
Moreover, video files must play in QuickTime (for example, not all.mp4 files will play in Quicktime).
- Right-click the video file and select Properties (Windows) or Information (OS X).
- Find the entry for "File Type" or "Kind". If this .mkv, .wmv, .avi file, then it needs to be converted.
- Check the file in QuickTime. If this .mov, .m4v, .mp4 file, load it into QuickTime to make sure it plays. If not, you need to convert it; otherwise, skip to chapter two.

Step 2. Download and install Handbrake
It is a free video converter that supports Windows and OS X. It will allow you to convert video files to iTunes supported format.
- You can download HandBrake from handbrake.fr.
- Better not to use online converters. They often have limitations on the size of the video file, and uploading and downloading videos can consume a significant amount of traffic.

Step 3. Launch HandBreak
Find the shortcut of this converter on your desktop or in the Applications folder. When converting video files, most of the settings can be left as default.

Step 4. Click "Source" (in the upper right corner)
You will be prompted to select a file to convert.

Step 5. If you want to convert multiple video files at once, click "Folder"
All required video files must be located in one folder. If you want to convert one video file, click "File" and select the video file.

Step 6. Next to the Destination field, click Browse
Select the folder where the final video files will be placed. Also enter the name of the final video file.

Step 7. Check the "Standard" preset (on the right side of the screen)
If you don't see the presets bar, open the Presets menu and select Show Presets Bar.
With the "Standard" preset, any video file will be converted to.mp4 format, which can be imported into iTunes

Step 8. Click "Start" to start the conversion process
It will take from several minutes to several tens of minutes (if the video file is large).

Step 9. Check the resulting video
To do this, play it back in QuickTime and make sure the conversion was successful. In most cases, you shouldn't notice any degradation in video quality.
Method 2 of 2: Import

Step 1. Rename video files with dots in their names (often video files downloaded from torrent trackers “sin” with this)
Remove the dots from the titles as they can cause problems when importing videos to iTunes.
Right click on the file and select Rename to change the name of the video file

Step 2. Launch iTunes
Make sure you have the latest version of iTunes installed.

Step 3. Import the video file
Click File (Windows) or iTunes (OS X) and select Add File To Library (Windows) or Add To Library (OS X). Find the converted video and select it.
- If you don't see File on Windows, press the Alt key.
- You will not receive any messages or confirmations when adding video files.

Step 4. Click on "Movies"
This button is located in the row of buttons along the top of the iTunes window and looks like a film strip.

Step 5. Go to the "Home Videos" tab
Any imported video will be added to the Home Videos tab. If the imported video does not appear on this tab, you have converted the video file to a format that iTunes does not support.

Step 6. Transfer your video to your Movies or TV Shows library
It is very difficult to find the video you want in the Home Video tab. Therefore, it is better to sort the video files into different media libraries.
- Right-click on the video file and select Info.
- Go to the "Parameters" tab (in the window that opens).
- Next to Media Type, click Home Video to select the library where you want to move your video file.
- Click OK to save your changes. You should now be able to find your video in the specified library.

Step 7. Synchronize the video files with your iOS device
Read this article for details on synchronization.