Free converter · Remux (container swap)

Convert M4V to MOV

Runs in your browserNo uploadUp to 100 MB

Short answer

Drop your M4V file into the converter below and download the MOV file. It runs in your browser with FFmpeg, for files up to 100 MB; nothing is uploaded. The video and audio streams are copied into the MOV container without re-encoding, so quality and file size stay the same. If a stream cannot go into MOV (PCM audio cannot go into MP4, for example), the converter re-encodes to H.264 video and AAC audio in a QuickTime MOV instead.

Maximum file size: 100 MB. The first conversion loads a ~30 MB converter engine, once per visit. Nothing is uploaded - conversion runs on your device.

Streams are copied into QuickTime; copy-protected iTunes files cannot be converted. · Remux (container swap) · Browser-side via FFmpeg WASM - nothing uploaded.

Key takeaways

  • The streams were copied: the video and audio checksums were identical before and after, and the 8.88 MB file became 8.88 MB (0.0%).
  • The result holds: Video: h264 1920x1080; Audio: aac 48000 Hz 2 ch.
  • In your browser the same conversion of a 3 second clip took 0.09 seconds on the single-thread engine; natively, the 10 second clip took 0.09 seconds.
  • Next to it: M4V to AAC (-98.2%), M4V to AVI (-70.6%), M4V to GIF (+592%).

Measured: M4V to MOV

The converter's own ffmpeg arguments, run on a 10 second 1920 × 1080 excerpt of Big Buck Bunny (an animated film, not camera footage) saved in M4V. The browser column is the same arguments on the single-thread WebAssembly core with a 3 second excerpt, in a headless run; your device will differ. Results describe this clip and these encoders.

CheckResult
ModeStreams copied (no re-encoding)
InputM4V, 8.88 MB
OutputMOV, 8.88 MB (0.0%)
Output streamsVideo: h264 1920x1080; Audio: aac 48000 Hz 2 ch
Time, native, 10 s clip0.09 s
Time, browser engine, 3 s clip0.09 s
Video checksumIdentical
Audio checksumIdentical

Because nothing is decoded, a copy takes a fraction of a second whatever the length of the video.

M4V vs MOV

M4VMOV
Full nameApple MPEG-4 videoQuickTime File Format (Apple)
What is insideH.264 video with AAC audio, the same structure as MP4H.264, HEVC or ProRes video with AAC or PCM audio
CompressionDepends on the codec insideDepends on the codec inside
Best forApple TV and iTunes; files bought from iTunes may be copy-protected and cannot be convertediPhone recordings and Final Cut Pro projects

What you get

The same streams in an MOV file. When a stream cannot be copied, the converter writes H.264 video and AAC audio in a QuickTime MOV.

Where you can upload MOV

PlatformMOVWhat the platform documents
TikTokAcceptedYes - TikTok documents MOV uploads through its Content Posting API.
Instagram ReelsAcceptedYes - Instagram accepts MOV as well as MP4 for Reels.
Instagram FeedAcceptedYes - Instagram accepts MOV as well as MP4 for feed videos.
YouTube ShortsAcceptedYes - YouTube (and Shorts) accepts MOV uploads directly.
X (Twitter)PartlyYes in X Media Studio - MOV support in other X upload surfaces is not established here.
Facebook ReelsUnclearCurrent MOV support for Facebook video uploads has not been reverified.
PinterestPartlyPartially - MOV works from the Pinterest app, but not on the web uploader.
LinkedInAcceptedYes - LinkedIn documents MOV for organic video on desktop, iOS and Android.
SnapchatUnclearMOV support for Spotlight is not established by the linked Snapchat help page.
ThreadsUnclearCurrent MOV upload support on Threads has not been reverified.

Planning a bigger file

These are estimates scaled up from the 10 second clip. Real files differ with content, resolution and bitrate, so treat them as an order of magnitude, not a promise.

Length of the video or recordingInput size (like ours)MOV sizeTime in your browser
1 minute53.29 MB53.29 MB2 seconds
10 minutes532.91 MB532.91 MB18 seconds
1 hour3197.43 MB3197.45 MB1.8 minutes

An M4V file of this kind reaches the 100 MB limit of the converter after about 2.0 minutes; converting it would take roughly 4 seconds on the single-thread engine, and the MOV would be about 104.86 MB.

M4V and MOV next to their neighbors

The same clip through other conversions with the same source or the same target.

ConversionHowSize changeTime (native)
M4V to MOVCopy0.0%0.09 s
M4V to AACRe-encode-98.2%0.30 s
M4V to AVIRe-encode-70.6%1.5 s
M4V to GIFRe-encode+592%5.5 s
M4V to M4ARe-encode-98.2%0.30 s
M4V to MKVCopy-0.1%0.11 s
M4V to MP3Re-encode-98.2%0.24 s

Choosing MOV

MOV: QuickTime File Format (Apple). iPhone recordings and Final Cut Pro projects. M4V: Apple MPEG-4 video. Apple TV and iTunes; files bought from iTunes may be copy-protected and cannot be converted.

  • Use this conversion when a program wants the other container; the picture and sound stay exactly as they were.
  • If the destination states the format it accepts, use that and nothing else.

Questions people ask

Is this M4V to MOV converter free and private?

Yes. It is free, needs no account and runs entirely in your browser, so the file never leaves your device.

Will converting M4V to MOV reduce quality?

Not when the streams fit MOV: they are copied unchanged. Only if a stream has to be re-encoded is there a small, usually invisible loss.

Is there a file size limit?

Files up to 100 MB. The first conversion downloads a converter engine of about 30 MB once per visit; larger files are better handled by a desktop app such as HandBrake or FFmpeg.

How do I convert M4V to MOV?

Choose the file in the converter above and download the MOV. It runs in your browser with no upload.

Will converting M4V to MOV reduce quality?

No. The streams are copied, and in our test the checksums were identical.

Why did the file size change by 0.0%?

A copy only changes the container, so the size stays about the same.

How long does it take?

A 3 second clip took 0.09 seconds in the browser engine in our test; time grows with the length of the file.

How long will an M4V file of 100 MB take?

At the speed we measured in the browser engine, about 4 seconds for a file like our clip. Your device and the content will change it.

Is my file uploaded?

No. The conversion runs in your browser.

Is there a size limit?

Files up to 100 MB. The first conversion downloads a converter engine of about 30 MB once per visit.

More converters

Sources and how we checked

  1. MDN: Media container formats
  2. MDN: Web audio codec guide
  3. MDN: Image file type and format guide
  4. FFmpeg documentation: stream copy
  5. FFmpeg Documentation: ffmpeg (stream selection, -map, -c copy) (read 2026-10-09)
  6. MDN: Media container formats (read 2026-10-09)
  7. Blender Foundation: Big Buck Bunny (CC BY 3.0), the clip used for the measurements (read 2026-10-09)

Reviewed October 8, 2026. What the converter writes was measured with ffprobe on the same FFmpeg build your browser downloads; format descriptions follow MDN's media guides.