Convert MOV to MP4

Where MOV files come from

MOV is Apple's QuickTime format, around since 1991. iPhones and iPads record in it, Macs save screen recordings in it, and many Canon, Nikon, Fujifilm and Panasonic cameras write it too. Plug an iPhone into a PC and its videos sit in the DCIM folder as IMG_ files ending in .MOV. Inside there is almost always H.264 or HEVC video, the same kinds of picture an MP4 carries, so for most clips only the wrapper has to change.

The usual reasons to switch: an upload form that lists only MP4, a smart TV that skips MOV files on a USB stick, an older editing program, or a work system that accepts a single format. MP4 is the one nearly everything takes. Because MP4 grew out of QuickTime in the first place, the two are built alike, which is why so much can be copied rather than converted.

What is copied and what is converted

A copy is exact, so the MP4 comes out about the size of the MOV. Camera clips with uncompressed sound are the common mixed case: the picture is copied and only the sound is converted, so they still go quickly. ProRes is an editing format that Octoolo does not copy into MP4; it often takes a gigabyte or more a minute, so its H.264 version is a small fraction of the size while keeping high quality. If the MOV has several sound tracks, the MP4 gets every one of them.

HEVC clips on a Windows PC

iPhones have recorded HEVC by default since iOS 11, under the High Efficiency setting. Copying keeps the HEVC, so the MP4 stays small and sharp, and Octoolo tags it so iPhones and Macs still recognize it. Windows is the catch: VLC brings its own HEVC decoder, but the Media Player and Photos apps only play it once Microsoft's HEVC Video Extensions are installed, and many PCs do not have them.

If the MP4 is for a PC like that, an older TV or an editor that cannot read HEVC, choose High instead of As it is. The picture is then converted to H.264, which plays practically everywhere, and the file grows, because H.264 needs more data for the same detail. HEVC to H.264 goes through it step by step.

What turns a copy into a conversion

As it is copies a stream only when nothing about it has to change. Anything under More settings that alters the picture, such as a smaller Size, fewer Frames a second or another Video codec, means the picture is encoded again. The sound works the same way: a new bit rate, sample rate or channel count re-encodes it, while the picture can still be copied.

That is handy for a sharing copy. A minute of 4K from a recent iPhone runs to well over 100 MB, too much for most email and many chats. Choose Balanced (about half the size) or Small, with a Size of 1080p or 720p and 30 frames a second. Octoolo never scales up or adds frames: sizes above the original are greyed out, a higher frame rate is simply ignored, and Put these back as they were undoes your changes.