Convert m4a files to mp3

I'm cleaning up my wife's music files. She uses Apple devices (iPhone/iPad) but a Windows laptop. Music files all over the place, probably because the old iTunes did it that way. A lot of MP3 files, but also a ton of M4A/M4P files. I'd like to convert all of them to MP3.

Does anyone here use a good m4a > mp3 converter? I'd like audio quality to stay the same. Also, not an online converter, she has hundreds of files.

Obviously a Google search shows hundreds of results, but if someone here uses a legit one, I'd love a recommendation. Thanks!

PS: I did search here, but nothing returned in last 2-3 years.

Actually there are not hundreds of choices because "under the hood" most programs use either FFMPEG.(a command line converter) or one of a handful of other choices. They all work well. So its a matter of choosing a Windows GUI that suits you.

I like FFMPEG Batch, which is free, very flexible, and fairly easy to use.

Sadly that is not possible. Converting one lossy format into another one always degrades the sound. So if preserving audio quality is important to you and to her, you should avoid this type of conversion.

You haven't told us why you want to convert a newer music format into a much older one. Is there a compelling reason? The M4a format delivers better quality for a given file size. And almost all players these days can play both types....


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Thanks for the education! In your experience, how significant is the conversion degradation? Noticeable? Or something that's going to get lost in a lossy format anyway?

Reason: I'm moving her music (and mine) to a common server, and wanted to make it all the same format, merely for convenience sake. There are a few differences (eg, can't make "track #" look the same), and I thought it would be easier if they were all MP3. I have about 40,000 tracks, she has about 1,000. Mine are all MP3, hers are all over the place.

Edit to add: Space isn't a concern (I have 4TB avail). But I don't want to give up too much quality if it can be helped.

It certainly can be, or not. The sensitivity of people to distortion and bandwidth variations varies greatly, and a lot depends on the quality that you start with. The higher the initial quality of the source file, the less likely that the degradation will be noticable. You could convert a few files and let her do some listening tests with both formats.

Sure but I don't see how having two music file formats is problematic. Many, many people (including me) have both and they play together nicely.

We have gotten way off topic for this forum. To learn more about lossy to lossy conversions, please try the Hydrogen Audio Forums
Good luck!

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Thanks, off to research...

Converting from lossy to lossy will definitely introduce a drop in quality. Depending on the current quality, the drop will likely be noticeable.

For the record, I also have a household with a mix of devices from Windows, Android, and iOS worlds. For a long time now I have been using Apple Lossless m4a files, but I still have 1000’s of older tracks that were ripped in mp3. All behave well together in my libraries, and I have a “mild” case of metadata OCD. :yum:

If you are having any specific issues with getting your tracks or other tags to work in harmony, let me know which ones and I can share how I deal with them.

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well, surely degrades but using mp3 320kbit will be not audible. (from my point of view its inpossible that difference is audibal, but this is a tiresome topic of disputes. yea, sure, measureable but.... )

Do you really need mp3? ever thought about FLAC?
But be aware, if you use choice of hardware devices MP3 320kbit would be better choice.

The second important point is using an good encoder. FFMPEG is a good choice.
call could be something like

ffmpeg -i "inputfile.mp4a" -ar 41000 -b:a 320k -y "outputfile.mp3"

(you can use parameter to set output format parameter or autodetect by file extension)

You can write Batch to do batch processing or use an simplefied gui for doing that.
For example mediapurge can do convert by using ffmpeg (need to be configured as external decoder).
But you could even do an

dir /b /o:n

and build an batch with call posted above.


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quick question.
some time ago i converted many files from MP3 to M$A. but i can't remember what i used.
actually, maybe i did a fresh YT download of all my Playlists directly into M4A, so maybe that negates my whole question,
which was, if i convert from MP3 to M4A - which is meant to be a better quality - do i still get a quality degrade?

kind regards

Any kind of conversion cannot improve the quality of the source. At best, the quality will stay the same. But it will not become better.

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MP3 is a "lossy" format. Whatever you convert into mp3, you will decrease the audio quality.
In short "Lossy compression dramatically reduces the file size but doesn’t maintain audio quality."

M4A is a container format only. It can contains lossy AAC audio or lossless ALAC.

There is no "better quality" if you convert from one audio format to another.
In the best case, you can keep the source audio quality and reduce the file size.
In the worst case, you will reduce the audio quality and get only slightly smaller files.

Additional informations: Lossless vs. lossy audio: FLAC, WAV, MP3, and other formats

Side note:

If you really use YT as audio quality source, then forget about all the audio conversion. Your source quality will be that bad in 99 of 100 tracks, that you don't get any advantage converting them into any other target format. A "bad" source quality will never be better just because you convert it.

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this is true maybe ...

eg you can't make up (audio) data that is not there, but on the other hand, in other contexts, there are programs that extrapolate and add missing data.

also i would think that there are audio (and video), and certainly graphical (photo) programs, that DO repair existing damage/faults in the original data, so i suspect that are similar programs that do the same for audio and video, although i have not looked for any such programs atm.

We are in the Off-Topic forum, therefore:

Personally, I don't believe that such software really works.

Just imagine a picture with a simple red circle. In the middle of this circle you can see a single yellow dot. Is this single yellow dot a damage? Or is it the artist intent to paint this single yellow dot exactly where it is?
If you see old photos from yourself as little child, with this typical artefacts of hair, dust, sticky spots, mold and so on then you could say: I would like to remove them.
But if you see photos or videos newly created with this "retro" or "vintage" style, why would you "improve" them, even if the artist made it specially like this?

The same is true, IMHO, for music. How can you now if an audible scratch in your track is a damage? Maybe the artist made this scratch for a specific reason? If you hear a scratch, why would you eliminate it, if it is part of the song?

I don't think repair software can guess which scratch is intentional and which is real recording damage.

There may be software that detects the yellow dot in my example image and eliminate it by filling it with the same color of the surrounding red circle.

Is this really what you want to achieve? Even automated for many tracks at once?