How to convert iPhone MOV videos to MP4 without losing quality

• MOV and MP4 are containers: the “box” holding the video and audio.
• H.264 and HEVC (H.265) are codecs: how the picture is compressed. H.264 plays everywhere; HEVC is smaller, but some browsers and devices can’t play it.
• If your MOV is already H.264, just switching the box to MP4 is enough: no quality loss and it takes seconds.

With the free tool ffmpeg, this command copies the video and audio as they are into an MP4. If the result plays fine in your browser, you’re done:

ffmpeg -i video.mov -c copy -movflags +faststart video.mp4

If the video is HEVC and doesn’t play in some browser, convert it to H.264 with AAC audio. At -crf 20 the quality difference is practically invisible:

ffmpeg -i video.mov -c:v libx264 -crf 20 -preset medium -c:a aac -b:a 160k -movflags +faststart video.mp4

• HandBrake (free, Windows/Mac/Linux): open the MOV, pick the “Fast 1080p30” preset (or your resolution) and export as MP4.
• On iPhone, Settings → Camera → Formats → “Most Compatible” records in H.264 from the start (slightly larger files).
• When sharing from the Photos app, some options convert to a compatible format automatically.

Dembed accepts MOV files directly, up to 20 GB, and keeps your original without re-encoding it. If your video is HEVC, converting it to H.264 before uploading makes sure it plays in all your viewers’ browsers.