How to Convert MP4 to MOV for QuickTime

MP4 and MOV are both container formats. They hold video and audio streams but do not define the quality of those streams. QuickTime Player can often play an MP4 file directly. You only need a real conversion if the MP4 uses a codec QuickTime does not support, or if an app or workflow specifically requires a .mov file. This guide covers both cases.

Before you start

• Make a copy of the original MP4 and keep it until you have confirmed the new file works.
• Try opening the MP4 in QuickTime Player first. If it plays with picture and sound, you may not need to convert it.
• Decide whether you need a lossless container change (remuxing) or a re-encode. Remuxing keeps the original streams. Re-encoding creates new streams and can reduce quality.
• Check free disk space. A re-encoded file, especially in an editing format such as ProRes, can be much larger than the source.
• Know where the processing happens. QuickTime Player and FFmpeg run locally on your computer. Online converters upload your file to a remote server.

If you use an online converter, treat its privacy and file deletion claims as statements to verify. Read its terms before you upload personal recordings, video calls or client footage. For sensitive material, a local method is the safer choice.

Step-by-step instructions

Option 1: Export from QuickTime Player (macOS)

• Open the MP4 in QuickTime Player with File > Open File.
• If the video plays correctly, choose File > Export As.
• Pick a resolution that matches your source so the video is not downscaled.
• Choose a name and location, then save. The exported file uses the .mov extension.

Exporting from QuickTime Player encodes the video again, so the result is not a bit-for-bit copy of the original streams. The export options vary between macOS versions. Some versions let you choose between H.264 and HEVC, for example. If QuickTime Player cannot open the MP4 at all, this option will not work, and you should use Option 3.

Option 2: Remux with FFmpeg without re-encoding (macOS, Windows, Linux)

FFmpeg is a free command-line tool. Remuxing moves the existing streams into a MOV container without changing them, so there is no quality loss and it is usually fast. Open a terminal in the folder that contains your file and run: ffmpeg -i input.mp4 -c copy output.mov

Replace input.mp4 and output.mov with your own file names. The -c copy option tells FFmpeg to copy the streams as they are. This works when the video and audio codecs, such as H.264 or HEVC video with AAC audio, are already compatible with QuickTime. If FFmpeg reports that a codec is not supported in the container, use Option 3.

Option 3: Re-encode with FFmpeg when codecs are incompatible

If the MP4 uses a codec QuickTime cannot play, convert the streams to H.264 video and AAC audio: ffmpeg -i input.mp4 -c:v libx264 -crf 18 -preset medium -c:a aac output.mov

The -crf value controls quality. Lower numbers give higher quality and larger files. Around 18 is a common starting point for visually close results. If only the audio is the problem, keep the video as it is and convert just the sound: ffmpeg -i input.mp4 -c:v copy -c:a aac output.mov

If you need the MOV for editing rather than playback, you can encode to ProRes: ffmpeg -i input.mp4 -c:v prores_ks -profile:v 3 -c:a pcm_s16le output.mov. Expect a much larger file. A ProRes file does not restore detail that was lost in the original MP4.

Check the output

• Open the new MOV in QuickTime Player and play the start, middle and end. Make sure the picture, sound and audio sync are correct.
• In QuickTime Player, choose Window > Show Movie Inspector to see the format and resolution of the file.
• If you use FFmpeg, run ffprobe output.mov to list the streams. Confirm that both video and audio are present and that the duration matches the original.
• After a remux, the file size should be close to the original. A very different size suggests that streams were dropped or re-encoded.
• After a re-encode, compare a detailed or fast-moving scene with the original to judge quality before you delete anything.

Common problems and next steps

Renaming the file from .mp4 to .mov does not convert it. Sometimes the renamed file opens, because the two formats have a similar structure, but the result is unreliable. Some apps reject it or misread it. Use a real export or remux instead.

If QuickTime Player says the file is not compatible, the cause is almost always the codec, not the container. Check the streams with ffprobe input.mp4, then re-encode the unsupported stream as described in Option 3.

If the MOV plays without sound, the audio codec is probably not supported by QuickTime. Re-encode only the audio to AAC and keep the video stream copied.

If you are on Windows, note that Apple no longer supports QuickTime for Windows. FFmpeg can still create MOV files on Windows for someone who will use them on a Mac or in an editing application that requires MOV.

If the converted file is much larger than expected, check which codec you used. ProRes and other high-bitrate formats produce big files by design. For sharing or playback, H.264 or HEVC is more practical.