1Upload every file you want combined — at least two of them.
2Drag the uploaded items into the order you want; the order is taken from the list, not from the filenames.
3Start the merge, which joins matching inputs without re-encoding them and reconciles mismatched ones exactly once.
4Download the single combined M4A file.
Merge M4A FAQ
Does it matter if the inputs are different formats?
+
It does. M4A is an MP4 container holding AAC or ALAC audio — the default for iTunes and Apple Music files. Matching inputs take a fast, lossless path; mismatched ones have to be reconciled to a common format, which is slower and costs one encode.
Anything specific to M4A when merging?
+
Yes — an .m4a can hold either AAC or ALAC, so lossy and lossless files share one extension and have to be told apart by inspection. That is worth checking when the inputs did not all come from the same source.
How many files can I combine at once?
+
On the free tier a merge accepts two files at a time, which is deliberately higher than the single-file limit on other tools because merging one file is meaningless. A pass removes the cap entirely.
Is the merge lossless?
+
It is whenever the inputs already agree — the encoded data is copied straight through. It stops being lossless only when the inputs disagree and something has to be re-encoded to make them compatible, and even then it is one pass, not one per file.
Can I run Merge M4A on several M4A audio files at once?
+
Yes. Upload the set and they process in parallel with the same settings, which is the practical way to handle a podcast series or an album rather than repeating the job by hand.
Do tags and cover art survive?
+
Yes. ID3, Vorbis comments and MP4 metadata atoms are carried across, cover art included, so a processed file still sorts correctly in a music library. ReplayGain values are recalculated rather than copied, because a stale one is worse than none.
Does Merge M4A cost anything?
+
No. Merge M4A is free without an account and adds no audio watermark or spoken tag to the output. Your upload is deleted from the workers shortly after the job completes.
Is there a file size limit on Merge M4A?
+
Yes: free accounts process audio up to 200 MB per file, which at typical bitrates is several hours of material; ffmpeg does the decoding and encoding, exactly as it would on a desktop. That is the most generous cap on the site after video, and audio work rarely runs into it.
Why does a PNG site host Merge M4A?
+
PNG.to is built around the format you use when you cannot afford to lose a pixel: lossless, alpha-capable, and the correct answer for screenshots, logos, line art and anything with hard edges. Image work is rarely one step: people arrive to change a format and leave needing the picture a different size, a different weight or a different shape. Running Merge M4A on the same upload pipeline, the same size caps and the same account is the whole reason it is here rather than on a fourth tab.
What should I do with the result once Merge M4A is finished?
+
The converter on this site moves images to and from PNG, JPG, WebP, GIF and SVG — which is the step where the decision about transparency actually gets made. That is the step most people actually came for, and doing it after Merge M4A rather than before it means the conversion works from the file you finally settled on.
Is Merge M4A here the same tool the sibling sites run?
+
The engines are shared — the same libraries, the same workers, the same limits. What differs is the advice, and the advice here starts from one fact about the format this site is named after: there is no quality slider to get wrong — a PNG round-trips bit-exactly, so the only thing edits cost you is file size. A PNG site is opinionated about where PNG is the right destination and where it is not, and that judgement is worth more than the button.
Do I need an account, and does anything get kept?
+
No account, and nothing is kept: uploads are deleted from the workers shortly after the job finishes, and nothing you process is indexed, listed or used for anything else. Free accounts exist for history and batch size, not for access.
