Convexy

Convert MP4 to MOV on iPhone

MOV is Apple's QuickTime container — the format Final Cut, QuickTime Player and a lot of Mac tooling would rather be handed. Going the other way from MP4 is straightforward, and worth understanding before you do it.

Why anyone converts this direction

MP4 is the universal container, so converting away from it looks perverse until you have hit one of these:

If nothing on that list applies to you, you probably do not need this conversion. MP4 plays on more things than MOV does, and converting for its own sake costs you a re-encode for nothing.

What actually changes

Both MOV and MP4 are containers, not codecs. The MP4 specification was derived from Apple's QuickTime format and they share the same underlying box structure, which is why the same H.264 or HEVC video and AAC audio can live happily in either.

So in principle a MOV and an MP4 of the same footage differ only in the wrapper. In practice, Convexy re-encodes: it runs the file through Apple's video export pipeline at the resolution and codec you select, rather than rewriting the container around an untouched stream. That is a new lossy generation.

You get resolution and codec control in exchange, which a pure container rewrite cannot offer. But it is not a free operation, and pretending otherwise would be the sort of thing this app exists not to do.

Pick Original quality unless you specifically want to downscale. It is still a re-encode, but it will not discard resolution — which matters more here than usual, because MOV conversions are usually headed into an editor rather than out to a viewer.

Codec choice, for editors

Convexy offers H.264 and H.265 (HEVC).

If this file is going into an edit, H.264 at Original quality is the boring, correct answer. Neither codec is a true editing codec — ProRes would be, and Convexy does not produce it — but H.264 is the one your software will fight you least about.

Audio and resolution

The Include audio toggle is on by default. Turn it off and the audio track is dropped from the MOV entirely. That is occasionally what you want and, if you did not intend it, is a genuinely irritating thing to discover in an edit — so glance at it before converting.

Resolution presets are Low (480p), Medium (720p), High (1080p) and Original. Downscaling is a one-way door: the detail you drop is not coming back, and re-upscaling later just produces a soft, larger file. Downscale on the way out of an edit, not on the way in.

On your device, which is the point

Video files are large and often personal. A converter with a server has to move every byte of yours to a machine you have never seen, hold it there, and be trusted to delete it. That is a lot of trust for a file-format change.

Convexy has no server at all. The export runs on your iPhone or iPad using its own video hardware. It works in Airplane Mode, requires no account, and the footage never leaves the device.

How to do it

  1. Bring the MP4 into Convexy

    Tap Browse files to pick it from Files, choose it from Photos, or share it into Convexy from another app.

  2. Choose MOV

    Convexy lists only what the file can actually become — MOV, M4V, animated GIF, extracted audio, or a still frame.

  3. Set quality and codec

    Original quality and H.264 is the right default for anything heading into an editor.

  4. Check the audio toggle

    Include audio is on by default. Only turn it off if you actually want a silent MOV.

  5. Convert, then save or share

    The export runs on your device. Save the MOV to Files or Photos, or share it straight to your Mac.

Common questions

Is MP4 to MOV lossless?

Not in Convexy. Although the two containers are closely related and could in principle be swapped without touching the video, Convexy re-encodes through Apple's export pipeline at the quality and codec you choose. That is a new lossy generation. Pick Original quality to keep it as close to the source as the pipeline allows.

Is MOV better quality than MP4?

No. Neither container has a quality of its own — they both just hold a video stream. What determines quality is the codec, the bitrate and the resolution inside. A MOV and an MP4 of the same footage at the same settings look identical.

Why does Final Cut or QuickTime reject my MP4?

Usually the codec or the internal muxing, not the container. "MP4" spans a very wide range of arrangements, and some tools are pickier than the specification requires. Re-exporting to MOV with H.264 selected regularises the file and typically resolves it.

Can I convert MOV or MP4 to ProRes?

No. Convexy produces H.264 and HEVC only. ProRes is a professional intermediate codec and is not something Convexy writes — if your edit specifically requires ProRes, you will need a desktop tool for that step. Better to know now than after the trial.

Does the conversion upload my video?

No. Convexy has no backend, so there is nowhere to upload to. Everything runs on your iPhone or iPad's own video hardware and works with the network switched off.