I have a large collection of videos in AVI and MKV formats, but I can’t import them into iTunes. I’ve tried dragging the files, and adding to the library from the File menu, but nothing works. Why is this?

iTunes has never supported AVI or MKV files, or a number of other video formats. The only way you can add these files to iTunes is to get them converted iTunes-compatible format. You can easily find a third-party video conversion app to do so.

The free HandBrake can be used to convert videos for adding to iTunes. Just choose a video as as source, pick a preset (iPhone/iPad/iPod/Apple TV…).

How to Convert Video with HandBrake

You can then import the converted video files into iTunes library by either dragging or adding from the File menu.

Actually, iTunes does support certain video formats. If you have video files in any of the following formats, you do not need to convert them at all.

H.264

• File formats: .m4v, .mp4, and .mov
• Video: Up to 768 kbits/sec, 320 x 240, 30 frames per second (fps), Baseline Profile up to Level 1.3.
• Audio: AAC-LC up to 160 kbits/sec, 48 Khz, and stereo audio.

MPEG-4

• File formats: .m4v, .mp4, and .mov
• Video: Up to 2.5 Mbits/sec, 480 x 480, 30 fps, Simple Profile.
• Audio: AAC-LC up to 160 kbits/sec, 48 Khz, stereo audio.

For more video sources supported by iTunes, please refer to iTunes Supported Video Content.