What happens when you convert M4V to MP4
- If the video inside the M4V is already H.264, the tool first copies the streams straight into the MP4. That takes seconds and loses nothing.
- If a copy is not possible, it re-encodes to H.264 video with AAC audio, which is slow in a browser: expect several times the video's length for HD footage, less at lower resolutions.
How to convert M4V to MP4 online
- Press "Choose M4V files" and select one or more files, or drag them onto the box. You can add files of any size your device can hold in memory.
- Adjust the settings if you need to: resolution and quality control the size of the result. The defaults suit most people.
- Press "Convert to MP4". The first audio or video conversion downloads the converter engine, about 32 MB, which your browser then keeps for next time.
- Save each MP4 with its download button. Close the tab and every trace of the files is gone from memory.
Why convert M4V to MP4?
M4V files usually come from iTunes films and TV shows and HandBrake exports. People convert them to MP4 because MP4 with H.264 plays on every phone, laptop, smart TV and website, and it is what YouTube, Instagram, TikTok and WhatsApp expect.
In short, M4V is good at what it was made for, and MP4 is the more practical choice when the file has to play, upload or edit somewhere else. M4V plays in Safari; Chrome plays unprotected M4V files, while MP4 plays in every browser, phone and smart TV.
How to convert M4V to MP4 on Windows, Mac, iPhone and Android
On Windows
Open this page in Chrome, Edge or Firefox, drag your M4V files in from File Explorer, and press Convert. Each MP4 is saved to your Downloads folder. If you prefer a desktop program, VLC can also convert M4V to MP4: choose Media, then Convert / Save.
On a Mac
Safari, Chrome and Firefox all work. Drag the M4V files from Finder onto the drop zone and the MP4 files land in Downloads.
On iPhone and iPad
Open the page in Safari and tap Choose M4V files. You can pick from Photos or from the Files app. The converted MP4 appears in Files, in the Downloads folder; to put it in your photo library, open it there, tap Share and choose Save Video.
On Android
Open the page in Chrome, tap Choose M4V files and pick them from Files or your gallery. The MP4 is saved to the Download folder, where any file manager can find it. Keep the screen on while a long video converts, because Android may pause a tab in the background.
Best settings for M4V to MP4
Leave Resolution on Keep original and Quality on Standard if the video only needs to change container: that is what lets the tool copy the H.264 stream straight into the MP4, which is fast and loses nothing.
If the file is too big, change either setting and the video is re-encoded with H.264. Quality uses the CRF scale: High is 20, Standard 23 and Smaller file 28. As a rule of thumb each step of about 6 on that scale halves or doubles the size. Dropping from 1080p to 720p usually saves more than lowering the quality, and it also makes the conversion much faster.
M4V vs MP4: the differences
| M4V | MP4 | |
|---|---|---|
| Full name | iTunes video | MPEG-4 Part 14 video |
| Type | video | video |
| Created by | Apple | the Moving Picture Experts Group |
| First released | 2003 | 2001 |
| Compression | Lossy | Lossy |
| Usually contains | H.264 video with AAC audio | H.264 or H.265 video with AAC audio |
| In a browser | plays in Safari; Chrome plays unprotected M4V files | plays in every browser, phone and smart TV |
| Common uses | iTunes films and TV shows and HandBrake exports | phone videos, YouTube uploads, social media and streaming |
| MIME type | video/x-m4v | video/mp4 |
About M4V and MP4 files
What is an M4V file?
M4V is nearly identical to MP4. Files bought from iTunes carry FairPlay copy protection, which no converter can legally remove; unprotected M4V files convert freely.
What is an MP4 file?
MP4 is the most widely supported video format, and H.264 video with AAC audio inside it plays on essentially every device made in the last fifteen years.
M4V to MP4 not working? Common problems
- The conversion is slow. Audio and container changes take seconds, but re-encoding video runs on your own processor. Lower the resolution to 720p, close other tabs, and keep the device plugged in.
- The tab stops or reloads on a very large file. Browsers limit how much memory one tab can use, around 2 GB and less on phones. Split long recordings or convert them on a computer.
- The M4V will not convert at all. Files bought from iTunes and commercial DVD or Blu-ray discs are copy protected, and no legitimate converter can read them. Home-made files convert normally.
Convert M4V to MP4 with ffmpeg
This converter runs ffmpeg inside your browser. If you would rather use the ffmpeg command line on your own computer, this command produces an equivalent MP4 with the same kind of settings:
ffmpeg -i input.m4v -c:v libx264 -crf 23 -preset veryfast -c:a aac -b:a 128k -movflags +faststart output.mp4Replace input.m4v with the name of your file. For a whole folder of M4V files, run the command in a loop, or drop them all on the converter above, which processes them one after another.
M4V to MP4 converter FAQ
Will I lose quality converting M4V to MP4?
A little. Both formats are lossy, so re-encoding compounds the loss slightly. Keep the default quality or higher and the difference is rarely noticeable.
Why is the MP4 a different size from the M4V?
It depends on the settings. At the defaults, the MP4 usually comes out close in size to the M4V; lower the quality for a smaller file.
Are my M4V files uploaded anywhere?
No. The conversion runs inside this browser tab using ffmpeg compiled to WebAssembly, so your files stay on your device. You can disconnect from the internet after the page and converter engine have loaded and it still works.
Can I convert several M4V files to MP4 at once?
Yes. Select or drop as many files as you like; they are converted one after another and each gets its own download button.
How do I open an MP4 file?
MP4 plays in every browser, phone and smart TV. MP4 is common for phone videos, YouTube uploads, social media and streaming.
Is this M4V to MP4 converter free?
Yes. There is no sign-up, no watermark and no limit on how many files you convert. The site is paid for by advertising, and because conversions run on your device there is no server cost per file.
Can I convert M4V to MP4 on my phone?
Yes. The converter works in Safari on iPhone and iPad and in Chrome on Android. Long HD videos convert more slowly on a phone than on a computer.