M4A → AAC
Unwrap M4A files into raw AAC streams without uploading anything.
Drop files here
or browse from your device
images · audio · video · documents · archives · up to ~500MB
Your first conversion lands here automatically — saved on this device only, never uploaded.
100% Private
Runs in your browser. No upload.
Instant
No queue, no server roundtrip.
Offline-ready
Works after first load.
Moving M4A audio to AAC is about compatibility and size — which players accept the file and how much disk or bandwidth it costs once it gets there. AAC (Advanced Audio Coding) earns its place here: efficient modern compression that sounds better than MP3 at equal bitrates. M4A is an MP4 container carrying AAC (or ALAC) audio — what Apple Music, Voice Memos and most modern recorders produce. At the same bitrate it beats MP3 on quality.
M4A is an MP4 container carrying AAC (or ALAC) audio — what Apple Music, Voice Memos and most modern recorders produce. At the same bitrate it beats MP3 on quality.
The audio is decoded and re-encoded, so the running time, channels and sample content stay intact while bitrate and file size follow AAC. Going from a compressed M4A file to any other lossy format is a second generation of compression — start from the highest-quality source you have when it matters, and expect a lossless target to grow the file rather than improve the sound.
What you gain with AAC: Efficient modern compression that sounds better than MP3 at equal bitrates.
Drop your M4A file above and Morphio decodes it locally, then re-encodes it as AAC using WebAssembly + the browser's native codecs. Nothing is ever uploaded — your files stay on your device. Batch as many files as your machine can handle. See exactly how in-browser conversion works.
Open the M4A to AAC page, drop your audio file on the drop zone and press convert. Morphio runs an FFmpeg build compiled to WebAssembly that runs inside the page, so the M4A data never leaves your device and no server ever receives a copy.
Sample rate and channel layout carry across, and you keep the original file untouched on disk. Converting M4A to AAC only rewrites the container and encoding you asked for — the source file on your disk is never modified.
Yes. The free plan covers 10 conversions a day with files up to 200 MB and adds no watermark or sign-up. Morphio Pro ($5/month, or $29 once for lifetime access) removes the daily cap and raises the per-file limit to 5 GB.
Morphio decodes the M4A file at full fidelity and re-encodes it at a high-quality AAC setting, so the difference is normally invisible or inaudible. What conversion cannot do is recover detail the original M4A file already threw away.
Yes — drop the whole batch in and each file is processed in turn on your own machine. The practical limit is your device's memory and patience, not a server quota, because nothing is queued anywhere else.
No. The conversion runs entirely inside your browser using WebAssembly, so the file never leaves your device — you can disconnect from the internet after the page loads and it still works.