To complete the conversion, you can download Brorsoft Video Converter for Mac.

In order to solve MP4 won't play in QuickTime on macOS High Sierra issue, an ultimate solution is to convert QuickTime unplayable MP4 to QuickTime supported format. However, in some cases, you still probably come across the error message like 'the movie could not be opened' when you try to open a MP4 file on QuickTime player with incompatible video codec. QuickTime can play most of MP4 videos with MPEG-4, MPEG-2, H.264 video codec and MP3, AAC codec. Convert unsupported MP4 to QuickTime format If you have an older dual core mac, which is struggling with HD video playback, give Mplayer OSX Extended a try. It also supports instant playback of MKV files and advanced styled subtitles in the ASS format. MPlayer OSX Extended is one of the fastest choices on OSX to play back HD H264 videos. You can open double windows if you want to actually view the playlist. No codec packs are needed and it's completely free. You can also use it to play DVDs, CDs, VCDs, and various streaming protocols. VLC PlayerĪ simple and open source cross-platform best media player for Mac to playback various type of video file. Here you can try find QuickTime player alternative to play MP4 files with ease. It is risky to download a codec pack that may bring adware/malware/virus to your computer. You can go to Softonic or CENT to get QuickTime MP4 codec pack to strengthen your QuickTime player. QT 7 Pro is powerful enough to deal with that, but at a certain cost - $29.99.

QuickTime 7 and above can handle MP4 files well.

Actually, we've worked out 4 solutions to fix the problem. More than one guys have the similar issue when playing MP4 in QuickTime on macOS High Sierra. I get the bar and it stops halfway through loading and just sits there.' 'I am using a Macbook Pro 13' (early 2015) and I recently updated my macOS to High Sierra over a week ago, and then I had problems with my MP4 videos using Quicktime. QuickTime MP4 Playback Problems in High Sierra

How to play mp4 on mac