Convert AAC to M4A
Repackage raw .aac streams as proper M4A files that phones, players, and editing apps recognize.
Free workspace
Keep repeat file work in motion after the first export.
Start here without an account, then move into retained files, OCR, and starter workflows when the task stops being a one-off.
Instant use
25 browser conversions / day
Retained files
7-day retained files
Secure processing
10 server jobs / month
Document tools
20 OCR pages / month
Conversion surface
Run the file task now.
The converter stays fast and simple. Workspace features only step in when retention, OCR, or repeat work actually adds value.
How it works
A short path from input to finished export.
The flow stays simple so you can get in, finish the job, and move on without extra setup.
Upload AAC Files
Drag and drop your AAC files or click to browse. You can queue several at once.
Convert in Your Browser
The first run fetches the conversion engine (a one-time ~31MB download); after that, AAC to M4A conversion happens entirely on your device — nothing is uploaded.
Download M4A
Save the converted file right away. Multiple files are bundled into a ZIP for one-click download.
Why FileMorf
A cleaner route for this conversion.
The tool keeps the core job lightweight while still giving you room to grow into retained, higher-value workflows later.
100% Private
All processing happens in your browser. Your files never leave your device.
Efficient AAC Encoding
M4A uses the AAC codec, which delivers better sound than MP3 at the same bitrate — the native format of the Apple ecosystem.
One-Time Engine Download
The first conversion fetches a ~31MB audio engine; your browser caches it, and everything runs locally from then on.
Details
Answers before you start.
The important questions, plus the nearby routes users usually need next.
AAC and M4A are the same codec in different clothes: .aac is a bare stream, .m4a is that stream inside an MP4 container with metadata, duration info, and seeking. Lots of software that plays M4A happily refuses bare .aac files. Converting gives the audio the container it was missing, so it behaves like a normal audio file — seekable, taggable, and accepted everywhere AAC is.
Slightly, in principle. AAC and M4A are both lossy codecs, and every re-encode discards a little more data — the audio equivalent of photocopying a photocopy. One conversion at the High setting is rarely audible; just avoid converting the same file back and forth repeatedly.
High encodes AAC at 256 kbps, Standard at 160 kbps, and Small at 96 kbps. AAC is more efficient than MP3, so each level sounds roughly like an MP3 one step higher in bitrate.
Nearly — M4A is AAC audio wrapped in an MP4 container. The container is what adds reliable seeking, duration display, and metadata tags, which is why bare .aac streams misbehave in software that handles M4A fine. Note that the conversion re-encodes the audio rather than repackaging it bit-for-bit, so pick the High setting to keep the loss negligible.
No. The entire AAC to M4A conversion runs locally in your browser. The only thing fetched is the conversion engine itself — a one-time ~31MB download that your browser caches. Your files never leave your device, and there is nothing for anyone else to store.
The first run downloads the audio engine — FFmpeg compiled to WebAssembly, about 31MB. Your browser caches it, so later conversions start immediately, whether you're converting one file or a whole batch.
Related routes
Keep moving through adjacent file work.
These are the next conversion paths people usually need after this one.
Next step
Convert now. Create a workspace when the job starts repeating.
Keep quick work frictionless, then move into retained files, document tools, and secure processing when that actually improves the workflow.