Convert M4A to AAC online
Free, no sign-up, no limits. Drop your M4A files, get AAC files back in seconds.
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Drop your M4A files here
or · multiple files accepted
Local conversion: your files never leave your device.
Why convert M4A to AAC?
You have a M4A file that will not open on one of your devices or applications. AAC is more widely supported for your use case: streams extracted from videos, digital recorders, streaming.
How to do it, step by step
- Drop your M4A fileinto the area at the top of the page (or several files at once). On mobile, tap the area and pick the file from your apps.
- Check the output format: AAC is already selected. For music, 192 kbps is transparent for most listeners and 320 kbps gives the maximum. For voice (memos, podcasts, lectures), 128 kbps is more than enough and halves the file size.
- Start the conversion.The FFmpeg engine loads once (≈ 10 MB), then each file is processed in a few seconds without leaving your device.
- Download your AAC, directly or as a .zip if you converted several files. The name and metadata (title, artist, cover art) are preserved.
The M4A format (MPEG-4 Audio)
M4A is Apple's audio container, used by iTunes, Apple Music, iPhone voice memos and Mac recordings. It usually holds AAC audio, sometimes ALAC (lossless). Very good quality at a small size, but poorly supported by some car stereos, MP3 players, Windows software and websites.
- Excellent quality at the same bitrate
- Native Apple format (iPhone, Mac, iTunes)
- Can hold lossless audio (ALAC)
- Limited compatibility outside the Apple ecosystem
- Rejected by many car stereos and older devices
- Less universal than MP3
The AAC format (Advanced Audio Coding)
AAC is the successor to MP3: at the same bitrate, the sound is better. It is the audio codec of YouTube, Apple Music, digital TV and most MP4 videos. A raw .aac file (without the M4A container) is rarer and less well supported than its .m4a equivalent.
- Better quality than MP3 at the same bitrate
- Standard for video and streaming
- Raw .aac file poorly compatible
- No metadata without a container
M4A vs AAC comparison
| M4A | AAC | |
|---|---|---|
| Compression | Lossy | Lossy |
| Typical size (1 min, music) | ≈ 1.2 MB (160k) | ≈ 1.2 MB (160k) |
| Common use | iPhone voice memos, iTunes purchases, GarageBand recordings, Mac Voice Memos | streams extracted from videos, digital recorders, streaming |
| Metadata (title, cover art) | Yes | Limited |
Frequently asked questions
Does converting M4A to AAC lose quality?
AAC is a lossy compressed format: a conversion always involves re-encoding. At 192 kbps or higher, the difference is inaudible in the vast majority of cases. Just avoid chaining several successive conversions.
Is the M4A to AAC converter free?
Yes, with no limit on the number of files, no sign-up and no watermark. Each file can be up to 200 MB.
Are my M4A files uploaded to the internet?
No. The M4A to AAC conversion is performed by FFmpeg directly in your browser (WebAssembly). Your files never leave your computer or phone.
How do I convert M4A to AAC on iPhone or Android?
Open this page in Safari or Chrome, tap the drop area, select your M4A file (from Files, Voice Memos, Downloads or WhatsApp), then tap "Convert". The AAC downloads to your files.
Can I convert several M4A files at once?
Yes, add all your files in one go. They are converted one after another and a button lets you download everything as a .zip archive.