M4V File (.m4v): What It Is and How to Open It

The basics

What is an M4V file?

M4V is the extension Apple uses for video in the MP4 format. It became familiar through the iTunes Store, which from the mid-2000s delivered the films and TV episodes it sold as .m4v files. Apple's video apps, such as iMovie and Final Cut Pro, can export it, and the free converter HandBrake uses .m4v for some of its MP4 files.

Inside, an M4V is an MP4: the same box structure, the same codecs (H.264 or HEVC video, AAC audio) and the same index tables. The differences are small: an M4V brand in the ftyp box, Apple-specific extras such as chapter tracks and Dolby Digital audio, and, for videos bought or rented from Apple, FairPlay copy protection.

Two kinds of M4V

Unprotected M4V files (your own exports, HandBrake output) are ordinary MP4s and play almost anywhere. Protected M4V files from Apple's store are encrypted and only play in Apple's apps, signed in to the account that bought them. Most M4V problems come down to which kind you have.

Anatomy

What's inside an M4V file

An M4V file has exactly the structure of an MP4: a sequence of boxes, each starting with a 4-byte size and a 4-letter type, some containing other boxes. Here is the box tree of a 1-second M4V we made for this page with FFmpeg (H.264 video, AAC audio, iTunes-style tags). It isn't offered for download. Offsets and sizes are in bytes; a few boxes are left out to save space.

tiny.m4v (box tree)

tiny.m4v: 1 second, 320×240 H.264 + AAC, written with faststart

offset    size      box
0         32        ftyp   file type
                           00 00 00 20 66 74 79 70 4D 34 56 20 00 00 02 00
                           4D 34 56 20 69 73 6F 6D 69 73 6F 32 61 76 63 31
32        2,242     moov   the index
40        108         mvhd   movie header: timescale, duration
148       1,019       trak   track 1: video
156       92            tkhd   320×240, display matrix
284       883           mdia
324       45              hdlr   handler type "vide"
369       798             minf
433       734               stbl   sample table
441       194                 stsd   sample entry "avc1" (H.264 Main)
635       24                  stts   timing: 25 frames, equal length
659       20                  stss   1 keyframe
679       216                 ctts   display offsets (B-frames)
935       120                 stsz   size of every frame
1,055     112                 stco   where each chunk starts
1,167     977         trak   track 2: audio
1,343     45              hdlr   handler type "soun"
1,456     106                 stsd   sample entry "mp4a" (AAC-LC)
2,144     130         udta   user data
2,152     122           meta   iTunes-style tags: ©nam (title), ©too (encoder)
2,274     8         free   empty filler box
2,282     44,272    mdat   the media: H.264 and AAC frames
46,554                     end of file

100 00 00 20 66 74 79 70
Size and type
The first box is 32 bytes (0x20) long and of type ftyp. As in every MP4-family file, there's no fixed signature at byte 0: file-type detectors look for ftyp at byte 4.
24D 34 56 20 (M4V )
The major brand
M4V with a trailing space is the only thing at the start of the file that differs from an ordinary MP4. It tells Apple's software the file follows its conventions. The other brands, isom, iso2 and avc1, say it's also a standard ISO media file with H.264 video, which is why other players accept it.
3moov
The movie box
Duration, tracks, codecs and the tables that say where every frame is. It's at the start here because the file was written with faststart, so it can play while downloading.
4hdlr "vide" / "soun"
One track per stream
Each trak declares what it holds. Files from the iTunes Store often have more tracks than this: stereo AAC, a Dolby Digital 5.1 track, closed captions or subtitles, and a chapter track.
5stsd "avc1"
The sample entry: which codec
avc1 is H.264 and mp4a is AAC. In a FairPlay-protected file this entry is replaced by an encrypted one with a sinf box describing the protection, which is how a player knows it needs a licence before it can decode anything.
6stts, stss, ctts, stsz, stco
The sample tables
Frame timing, keyframes, display offsets for B-frames, frame sizes and chunk positions, exactly as in MP4. Seeking is a lookup in these tables.
7udta / meta
iTunes-style metadata
Tags stored in an ilst list with four-letter keys such as ©nam (title) and ©too (encoding tool). Apple's video files also use keys for the show name, season, episode and the kind of media, which is how the TV app sorts films and episodes.
8free, mdat
Filler and media
An empty free box that readers skip, then mdat: the compressed H.264 and AAC frames, with no structure of their own. Without moov they can't be decoded.

Related formats

M4V vs MP4: what's different

	M4V	MP4
Structure	ISO base media file format: `ftyp`, `moov`, `mdat`…	The same
Brand in `ftyp`	Usually `M4V`	`isom`, `mp41`, `mp42` and others
Owner	Apple's convention on top of the standard	ISO/IEC 14496-14, an international standard
Copy protection	Optional FairPlay DRM for Apple store content	None in the format itself; streaming services add DRM separately
Typical extras	Chapter tracks, AC-3 audio, closed captions, iTunes tags	The same features are possible but less common
MIME type	`video/x-m4v`	`video/mp4`
Plays in browsers	Yes if unprotected and the codecs are supported	Yes, in every current browser

HandBrake's documentation puts it plainly: an MP4 and an M4V from HandBrake are the same file with a different extension. HandBrake picks .m4v when a file has AC-3 passthrough audio, SRT subtitles or chapter markers, because old QuickTime 7-based software only played those features with that extension; QuickTime X and iOS don't need it. You can change the default in HandBrake's preferences.

Other neighbours: MOV is Apple's older QuickTime format, with the same box design but its own brand and codecs such as ProRes. M4A is the audio-only member of the family.

Copy protection

Protected M4V files and FairPlay

Films and TV episodes bought or rented from Apple (the iTunes Store, now the Apple TV app) are protected with Apple's FairPlay DRM. The container stays an ordinary M4V, but the video and audio samples are encrypted, and the keys are tied to the Apple Account that bought them. Only Apple software that's signed in to that account, on a computer or device authorised for it, can get the keys and play the file.

On a Mac, iPhone, iPad or Apple TV: play it in the TV app, signed in with the account that bought it.
On Windows: use Apple's apps for Windows (the Apple TV app, or iTunes on older versions of Windows) and authorise the computer for your account.
On Android, smart TVs and consoles: use the Apple TV app where it's available; it streams your purchases rather than playing the downloaded file.
In VLC, browsers or editors: a protected file won't play. Players may show the duration and tracks, because the index isn't encrypted, but the picture stays black or the file is rejected.

Renaming doesn't remove protection

Changing a protected .m4v to .mp4 doesn't make it play elsewhere: the samples are still encrypted. Removing DRM generally breaks the store's terms and, in many countries, the law. If you need a film on another device, use the store's own app on that device.

If a file came from Apple's store and plays only in the TV app, it's protected. Other tools can still read its structure, so ffprobe lists the tracks, but they can't decode the picture or sound.

On the web

Does an M4V file play in a browser?

An unprotected M4V is an MP4 to a browser, so the same rules apply: H.264 with AAC plays in Chrome, Edge, Firefox and Safari; HEVC plays in Safari and elsewhere only with a hardware decoder; AC-3 audio may play silently. A FairPlay-protected file from a store download doesn't play in any browser.

In a web page, it's safest to label the file as MP4 so every browser gives it a try:

video.html

<video controls playsinline>
  <source src="clip.m4v" type="video/mp4">
</video>

If you control the server, serving .m4v files as video/mp4 (or video/x-m4v) avoids the generic application/octet-stream type, which makes some browsers download the file instead of playing it.

Troubleshooting

Why won't my M4V play? Common problems and fixes

Symptom	Usual cause	Fix
Plays in the TV app, not in VLC or on Android	A FairPlay-protected purchase.	Play it in Apple's app on that device; renaming or converting won't work.
"Not authorised to play" on a computer	The computer isn't authorised for the account that bought the video.	Sign in with that account and authorise the computer in the TV app or iTunes.
A non-Apple app won't open the file	The app checks the extension, not the content.	For your own unprotected files, rename to `.mp4` or remux: `ffmpeg -i in.m4v -c copy out.mp4`.
Picture but no sound	The default audio track is AC-3 (Dolby Digital), which the player can't decode.	Pick the AAC track in the player, or convert the audio: `-c:v copy -c:a aac`.
Sound but black picture	HEVC video on a device without an HEVC decoder.	Re-encode to H.264: `ffmpeg -i in.m4v -c:v libx264 -crf 20 -c:a copy out.mp4`.

How to

How to open, edit and convert an M4V file

macOS: QuickTime Player or the TV app opens it; iMovie and Final Cut Pro import unprotected files.
Windows: the Media Player app plays unprotected M4V files with H.264; VLC plays the rest. Protected purchases need Apple's own app.
Linux: VLC or mpv, for unprotected files.
Phones: iPhones and iPads play M4V files in the TV app or Files. On Android, VLC plays unprotected files.
Convert to MP4: for an unprotected file this is a remux, fast and lossless: ffmpeg -i in.m4v -c copy out.mp4. HandBrake converts it with re-encoding if you also want a smaller file.
Inspect it: ffprobe in.m4v lists the tracks and codecs; MediaInfo shows the same in a window.

Renaming vs remuxing

Renaming an unprotected .m4v to .mp4 works in practice, because the content is MP4. Remuxing with -c copy takes just as little time and also gives the file a standard MP4 brand.

Security

Is an M4V file safe?

Metadata in your own videos. An M4V exported from a phone video can keep its recording date and location. ffprobe lists the tags, and ffmpeg -i in.m4v -map_metadata -1 -c copy out.m4v removes them without re-encoding.
Decoder bugs. An M4V can't run code, but a crafted file could exploit a flaw in a video decoder. Keep your system and players updated.
Fake "converters". Sites that promise to unlock purchased videos are a common source of malware. Stick to the store's own apps for protected files.

Sample files

There are no sample M4V files on this page. To make one for testing, run ffmpeg -f lavfi -i testsrc2=duration=5:size=640x360:rate=30 -f lavfi -i sine=frequency=440:duration=5 -c:v libx264 -pix_fmt yuv420p -c:a aac -movflags +faststart -f ipod test.m4v, or use the MP4 samples renamed to .m4v.

Put it online

Have an M4V file? Give it a link.

Drop an M4V on 99helpers and it gets its own address that plays in the browser when it's unprotected and its codecs are supported, H.264 and AAC playing everywhere. FairPlay-protected purchases can't play outside Apple's apps.

Put an M4V online

Questions

M4V files, frequently asked

What is an M4V file?

A video file in Apple's variant of the MP4 format, used for iTunes and Apple TV downloads and exports from Apple apps. Inside, it's an MP4 container with H.264 or HEVC video and AAC audio.

Is M4V the same as MP4?

Almost. The structure and codecs are the same; an M4V usually carries the brand M4V and may have Apple extras or FairPlay copy protection. An unprotected M4V is effectively an MP4.

Can I just rename .m4v to .mp4?

For an unprotected file, yes, and it will usually play. Remuxing with ffmpeg -i in.m4v -c copy out.mp4 is just as quick and cleaner. For a protected purchase, renaming changes nothing.

Why won't my iTunes movie play in VLC?

Films bought or rented from Apple are protected with FairPlay DRM, so only Apple's apps, signed in to the buyer's account, can decrypt them. VLC and other players can't.

How do I play an M4V file on Windows?

Unprotected files play in the Media Player app or VLC. Protected purchases need Apple's app for Windows (the Apple TV app, or iTunes on older systems) with the computer authorised for your account.

Does an M4V play in Chrome?

An unprotected M4V with H.264 and AAC does, like an MP4. A protected one doesn't play in any browser.

Why does HandBrake save .m4v instead of .mp4?

HandBrake uses .m4v when the file has chapter markers, SRT subtitles or AC-3 passthrough audio, for old QuickTime 7 compatibility. The content is the same MP4; you can switch the default to .mp4 in its preferences.

Related formats

Other file types explained

MP4 file MOV file M4A file WebM file MKV file 3GP file All file types

Keep going

Host an M4V file

Put an M4V online at its own address.

Share an M4V file

Send a video as a link instead of an attachment.

Host a presentation

Put slides and the videos they use online together.

Sources

Last reviewed 27 October 2026.