How to use it
- Choose or drop a MP3 file.
- Choose the output format, codec and available bitrate settings.
- Convert, review the result, then download your file.
When to convert MP3 to M4A
MP3 is already compressed with a lossy codec. Re-encoding it can reduce quality again. Use a copy of your original and check the exported audio before sharing it.
M4A is an audio-only MP4 container. AAC is a common choice for a small file with broad playback support. Converting to AAC can lose detail, so keep the original when you need an archival copy.
Common questions
Is it free without an account?
Yes. There is no signup, watermark, or charge to download. Your browser does the processing.
Which tracks are kept?
The primary audio track is converted. Video, subtitles, attachments and other audio tracks are omitted. Keep the source if you need them.
Why is a codec missing or a conversion blocked?
Codec support depends on your browser, operating system, device and source profile. The menus list available output encoders, and conversion checks the actual source. Try a current Chrome or Edge browser, another format, or Keep source codec for a compatible container.
Does conversion always preserve quality?
Keeping compatible encoded tracks avoids recompressing them. Re-encoding with a lossy codec can reduce quality. Lossless output preserves decoded samples but cannot recover detail lost in an earlier encoding.