[Fixed] QuickTime Player Can’t Open MP4 – 6 Efficient Solutions

What to Do if QuickTime Player Can’t Play MP4 Files?

• Restart your computer
• Reinstall QuickTime Player
• Convert video format
• Scan your computer for viruses and malware
• Use another supported video player
• Repair your video

Fix 1: Restart Your Computer

When you are using your Windows or Mac, your operations will produce some temporary and cached files. For example, there may be some residual files that remain on your computer but you don’t know this. These files can be the cause of QuickTime Player not playing files. Besides, many files are just running in the background. Some of them are unnecessary and they even cause problems.

It is easy to remove these files. You just need to restart your Windows or Mac. After that, you can use your QuickTime Player to play

Fix 2: Reinstall QuickTime Player

If your QuickTime Player not playing MP4 because it is corrupted or outdated, you can reinstall it to have a try. Since Apple has ended support for both the Windows version and Mac version of QuickTime Player, you need to go to the Apple official QuickTime download page to get the newest version and then install it on your computer. Please select a suitable version according to the operating system you are running.

Fix 3: Convert Video Format

If your QuickTime Player is not working, you can try converting MP4 to MOV, which is natively supported by QuickTime Player. You can use MiniTool Video Converter, a free video and audio format converter for Windows. This software is specifically designed for converting video and audio file formats. Below is a detailed guide to fix QuickTime Player can’t open MP4 using MiniTool Video Converter to convert videos.

Fast Track:

• Download MiniTool Video Converter
• Upload the target video
• Specify MOV as the output format
• Start the conversion process
• Check the converted video

Step 1: Obtain MiniTool Video Converter

Download and install MiniTool Video Converter. Then, run this application.

MiniTool Video ConverterClick to Download100%Clean & Safe

Step 2: Upload the Target File

In the default Convert Video tab, click on the Add Files option to import the target video.

Step 3: Configure MP4 as the Output Format

Click on the Gear icon to open the format settings window. Next, go to the Video tab and choose MOV. Then, select a proper resolution, such as 4K Video.

Step 4: Begin the Conversion

Expand the Output option to choose a storage location for the converted video. Then, click on the Convert button to begin the conversion process.

Step 5: Check the Converted Video

Once the conversion ends, the converted video will land on the Completed tab. Here, click on the Play icon to check it. Or click on the Folder icon to locate the converted video on the computer.

MiniTool Video Converter supports converting videos to MP4 in batches. It supports 1000+ formats, including 4K/FHD/HD MP4, MOV, MKV, AVI, WMV, M4V, and more.

Fix 4: Scan Your Computer for Viruses and Malware

If your computer is attacked by viruses or malware, the issue of QuickTime Player can’t open MP4 can also happen. Due to this, you can use antivirus software to scan your computer for viruses and malware and remove them.

Here are some choices for you:

1. Norton
2. Bitdefender
3. McAfee
4. BullGuard
5. Panda

All of them have both Windows and Mac versions. You can select one of them to scan your computer.

Fix 5: Use another Video Player

QuickTime Player is not the only video player. If it can’t play MP4 video or other types of videos, or it is not working on your computer, you can use another video player to have a try.

No matter whether you are running Windows or Mac, you can try one of the following video players to play videos:

1. VLC (VLC media player)
2. 5Kplayer
3. GOM Media Player
4. MediaMonkey
5. Kodi

Fix 6: Repair Your Video

Another possibility is that the video you want to play is corrupted or has a missing codec. In a situation like this, you need to use a professional video repair tool to repair the video or download a codec pack (if you are not a professional user, you’d better not download a codec pack because an unsafe source may bring viruses or malware to your computer). If you can’t do it by yourself, you can ask a professional for help.

QuickTime Supported Media Formats

In this part, we will show you two tablets of QuickTime Player supported video and audio formats.

Supported Video Formats

Supported Audio Formats

Summary

This article shares 6 fixes to fix QuickTime Player can’t open MP4, including restarting the computer, reinstalling QuickTime Player, converting the video format, scanning the computer for viruses and malware, using another video player, and repairing videos.

If you have any questions or suggestions, contact MiniTool official via support@minitool.com.

QuickTime Player Can’t Open MP4 FAQ