How to convert MP4 to M4A (AAC/ALAC)
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Upload your file
Drag and drop a file or click to select one. Keep this page open while the file uploads and converts.
- 2
Convert MP4 to M4A (AAC/ALAC)
NexMedia converts MP4 to M4A (AAC/ALAC) on its own servers. Processing time depends on the file size and how busy the queue is.
- 3
Download the converted file
When the conversion finishes, the download appears on this page. Your converted file is kept for 2 hours, then deleted.
About MP4
MP4 (MPEG-4 Part 14) is a container format standardised by ISO. It usually holds H.264 or H.265 video with AAC audio, and it can also carry subtitles and chapter markers.
It is the most widely supported video format: phones, browsers, smart TVs and video sites all play it.
The video inside an MP4 is almost always compressed with a lossy codec, so every re-encode loses a little quality.
Convert MP4 to M4A online free, no account required — M4A is an MPEG-4 audio file, usually holding AAC.
Change MP4 to M4A without losing quality — convert MP4 to M4A free in your browser.
Why is my MP4 file so large? MP4 video is already compressed with H.264 or H.265, so a lower bitrate or resolution shrinks the file at the cost of some quality.
About M4A (AAC/ALAC)
M4A is an MPEG-4 audio file: the MP4 container holding only audio, usually AAC and sometimes Apple Lossless (ALAC).
Music bought on iTunes, iPhone voice memos and many podcast downloads.
Whether an M4A is lossy or lossless depends on the codec inside, which the file extension does not show.
Why convert audio to M4A? It wraps efficient AAC audio with chapter marks and cover art in one small file that Apple, Android and Windows all play.
What changes when you convert MP4 to M4A
- The soundtrack of the MP4 is re-encoded as M4A at the default settings, so it is close to the original but not bit-identical.
- Only the sound is kept: the M4A file contains the audio track of your MP4, and the picture is dropped.
Settings you can change
Before you convert MP4 to M4A, you can adjust: Audio codec, Rate control, Audio bitrate, Quality (VBR), Sample rate, Channels, Normalize loudness, Trim start, Trim duration, and Keep tags.
Limits
Each plan sets a maximum file size and a number of conversions per day, and video and audio files also have a maximum length. Guests can convert files up to 100 megabytes and 5 per day; a free account raises this to 500 megabytes and 25 per day; paid plans go up to 100 gigabytes.
Your converted M4A file is kept for 2 hours, then deleted.
MP4 to M4A: questions and answers
Does converting MP4 to M4A reduce quality?
The soundtrack of the MP4 is re-encoded as M4A at the default settings, so it is close to the original but not bit-identical.
What is the difference between MP4 and M4A?
MP4 is a widely supported video container, usually holding H.264 video and AAC audio. M4A is an MPEG-4 audio file, usually holding AAC.
Can I change the settings when converting MP4 to M4A?
Before you convert MP4 to M4A, you can adjust: Audio codec, Rate control, Audio bitrate, Quality (VBR), Sample rate, Channels, Normalize loudness, Trim start, Trim duration, and Keep tags.
Do I need an account to convert MP4 to M4A?
No. You can convert MP4 to M4A without an account; signing in raises the file-size and daily limits.
How long is my converted M4A file kept?
The M4A file you convert from MP4 is kept for 2 hours, then deleted automatically.
When I convert MP4 to M4A, can I keep just the sound?
Only the sound is kept: the M4A file contains the audio track of your MP4, and the picture is dropped.
Will converting MP4 to M4A change my original file?
No. The conversion reads your MP4 and writes a new M4A file, leaving your original MP4 file untouched.