Convert MP4 to M4V

Apple introduced M4V in 2005 for video in the iTunes Store, and it is the ISO MPEG-4 container that MP4 is, carrying the same H.264 video and AAC audio. The file this page produces is written by the same muxer that writes MP4 files, with the same codecs inside. What you are changing is the four characters after the dot.

Those four characters do real work on a Mac. They decide which application claims the file, which icon it gets, and whether a library that sorts by kind treats it as a video the Apple TV app should show. That is a legitimate thing to want. It is also a small thing, and the next section is about what it costs.

If the only goal is the extension, change it in Finder or Explorer. The bytes are already correct, every player identifies video by its contents rather than its name, and the operation is instant and lossless. Very few pages about this pair will tell you that, and it is true.

Converting is worth doing when something else needs to change at the same time — the file is 4K and the destination is a 1080p device, the bitrate is higher than the library needs, or the source came from a camera or a screen recorder in a form the Apple side of the workflow has been fussy about. Then the re-encode is happening for a reason and the extension comes along with it.

H.264 at High profile with AAC audio, whatever the MP4 held. That is the combination every Apple device made in the last twenty years decodes in hardware, which is the point of choosing it rather than inheriting whatever was there.

If the MP4 held HEVC — anything recorded on a recent iPhone at default settings — this converts it down to H.264. The M4V will be more compatible with old hardware and larger for the same picture. Recent Apple devices play HEVC natively, so that particular trade is one to make deliberately rather than by accident.

The copy protection on films and shows bought from Apple is FairPlay, applied by Apple to the file they sell you. It is not a property of the M4V format and nothing on this page adds it. A converted file carries the extension and no protection at all.

That is the right outcome for your own video: a home movie, a recorded talk, a course you made. It plays in the Apple TV app, in VLC, on a phone and on a television, and it will still open when whichever service is involved has stopped existing. It also means this page cannot be used to make a file behave like a purchase, which is a boundary worth naming rather than leaving implied.

The MPEG-4 container has room for as many audio tracks as the source carried and the conversion keeps all of them, so a file with an original language and a dub arrives with both still selectable. That is not universal — extracting the same video to MP3 or AAC keeps only the first.

Chapter marks and embedded subtitle tracks are not carried across, and that gap bites hardest on exactly the sort of file people convert into an Apple library, where chapters are common. Keep the original alongside the M4V if those matter, or place a sidecar subtitle file next to it.

Software that trusts file names rather than file contents. Some Android players, some web upload forms with a fixed list of accepted types, and older Windows applications will refuse an M4V and accept the identical file renamed to MP4. Nothing has changed except what the software is willing to believe.

Browsers are the case worth remembering: a `<video>` element pointing at an M4V is a gamble on the server sending a sensible content type, where the same file as an MP4 simply plays. If the video is ever going onto a web page, that copy stays an MP4.

The strongest reason to do this is consistency. A library where every file carries the same extension sorts predictably, scripts over it do not need special cases, and a smart folder or a rule built on kind behaves the same for every item. Half a shelf of M4V and half of MP4 is the setup that produces surprises later.

If that is the goal, convert once when material enters the library rather than re-processing a shelf that already works. Each conversion is a generation of quality and the picture never comes back — which is an argument for renaming the files that are already fine and converting only what needed changing anyway.

Three quality bands, defaulting to balanced. Since the encode is happening, the high band is the right choice for anything going into a library you intend to keep, because that copy becomes the source for everything after it. Balanced is right for something you will watch on a phone or a tablet and then leave alone.

The resolution control only reduces. A 4K recording bound for an older Apple TV or an iPad is worth taking to 1080p once, here, rather than making the device scale every frame on every playback. Asking for a size larger than the source has is ignored, because upscaling adds bytes and no detail.

The conversion runs inside the browser tab using the codecs your machine already has. The video is never sent anywhere, which for this pair is less a privacy argument than an argument about proportion: uploading a gigabyte of home video to a server so that it can come back with a different extension is a strange amount of network for the result.

The free tier takes files up to 100 MB, there is no account and there is no daily count. If the file is larger than that and all you needed was the extension, the rename in the second section costs nothing and has no ceiling.