M4A to MP4 converter
Turn M4A audio into an MP4 video with your own picture or a plain colour, free. No upload, no sign-up, no watermark: it runs in your browser.
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Quick answer: To turn M4A audio into MP4 video, add the M4A file to the iHateFiles M4A to MP4 converter, choose a picture if you want one, and press the button. The conversion runs in your browser, so the file is never uploaded, and it is free with no sign-up, watermark or size limit. A video needs something to show, so one picture of your choosing, or a plain colour, stays on screen for the whole M4A.
An M4A is nearly an MP4 already
They are the same container. An M4A is an MP4 with no picture track, which is why iPhone Voice Memos and iTunes purchases save as one. What a video site or an editor needs is the picture track, and that is the only thing added here.
Renaming the file to .mp4 sometimes gets it to open, and still leaves a video with nothing to show, which sites tend to refuse. Here the sound is copied as it is and a real picture goes alongside it.
Should you convert M4A to MP4?
Worth doing when something only accepts video, such as YouTube or a social post. If you just need to send or play the sound, keep the M4A. The MP4 sounds no better and shows one still picture for its whole length.
What happens to the M4A sound
An M4A is already the audio half of an MP4, so its AAC sound moves across without being encoded again and the bitrate setting does not apply. An Apple Lossless M4A is encoded to AAC.
Where the MP4 picture comes from
From you. Choose a photo, cover art or a logo and it stays on screen for the length of the M4A; choose nothing and the screen is a plain colour. The shape can follow the picture or be set to widescreen, square or vertical, and a picture that does not fit either gets coloured bars or is cropped to fill. Most image formats work, HEIC photos included.
Why the MP4 is not much bigger than the sound
A picture that never changes takes almost no space as video, roughly 16 kbps plus a little for each repeat of the full picture. Nearly all of the MP4 is the sound itself, and a long recording does not cost a long video encode: the picture is prepared once.
M4A and MP4 side by side
| M4A | MP4 | |
|---|---|---|
| Inside the file | AAC | H.264 video with AAC sound |
| Compression | Lossy | Lossy |
| Carries sound | Yes | Yes |
| Shows a picture | No | Yes |
| Plays on | Apple devices, Android, browsers and most modern players | every phone, laptop, TV, browser and messaging app |
| Here | Read and write | Read and write |
What usually goes wrong
About the M4A. M4A, M4B, M4R and AAC are largely the same thing with different extensions. Renaming usually works, though it is not something to rely on.
About the MP4. Two MP4 files can behave completely differently depending on the codecs inside. A file that will not play is usually an unusual codec in an ordinary container, not a broken file.
How to convert M4A to MP4
- Add your M4A file. It is read from your disk and stays there.
- Choose a picture to show, or leave it on a plain colour.
- Press convert and the MP4 file is saved back to your device.
MP4 converter: everything that converts to MP4
Questions
How do I convert M4A to MP4?
Open this page, add your M4A file, choose a picture if you want one, and press the button. Your browser builds the video and saves it to your device. Nothing is uploaded.
Is this M4A to MP4 converter free?
Yes, completely. There is no account, no sign-in, no watermark and no daily limit, because there is no server doing the work. Your own device does it.
Are my files uploaded anywhere?
No. There is no upload endpoint. The conversion runs inside this browser tab, so your file never leaves your device. You can open your browser's network panel and watch: nothing carrying your file is sent.
Is there a file size limit?
No fixed limit. Because the work happens on your machine there is no server quota. The only ceiling is your own device's memory, which for video means very large files may be slow.
Do I have to add a picture?
No. Without one the video shows a plain colour, black unless you choose another, with your M4A playing over it.
Does the sound lose quality?
No, for an ordinary M4A. Its AAC sound is copied into the MP4 exactly as it is, so nothing is encoded again. An Apple Lossless M4A is the exception: that is encoded to AAC, at the bitrate you choose.
Can it make a waveform or lyric video?
No. One picture stays on screen for the whole of the M4A and nothing moves.
Will the MP4 work on YouTube?
It is an ordinary MP4: H.264 picture at 30 frames a second with AAC sound, which is what video sites ask for. Choose the shape that suits the site. Each one sets its own limits on length and file size.
Can I convert several M4A files at once?
Yes. Add as many as you like and they are converted one after another, then offered as a single ZIP. They all use the same picture.