What is a MOV file?
MOV is Apple's QuickTime container, introduced in 1991. Every iPhone video and every Mac screen recording is saved as a MOV. Inside, the video is usually H.264 or, on recent iPhones, HEVC, with AAC audio, which is exactly what an MP4 holds too. The two formats are close cousins; MP4 was standardised from the QuickTime design in 2001.
Why MOV causes trouble
Many Windows programs, Android devices, and web upload forms only accept MP4, and some reject MOV without looking inside. Because the streams are typically identical, converting MOV to MP4 is a container swap: the video is copied bit for bit into a new file in seconds, with no quality loss. Only if the codec is something MP4 cannot hold does a real re-encode happen.
HEVC MOV files from iPhones
Recent iPhones record HEVC by default for smaller files. HEVC inside MP4 plays on modern devices, but an older PC may show a black screen or refuse it. If that happens, force a re-encode to H.264, or set the iPhone camera to Most Compatible in Settings, Camera, Formats.
Frequently asked questions
Does converting MOV to MP4 reduce quality?
Not when the stream is copied, which is the normal case. A forced re-encode uses a high quality setting; the difference is not visible for typical footage.
Can I play MOV on Windows?
Windows 10 and 11 Movies & TV opens most MOV files; older tools do not. Converting to MP4 removes the doubt.