Convert MP4 to M4A — Free Online Converter

MP4 to M4A conversion extracts the audio track from an MPEG-4 video and saves it in the M4A container. M4A is essentially an MP4 file that contains only audio — it uses the same MPEG-4 Part 14 container with the audio-specific .m4a extension. Apple adopted M4A as the standard for iTunes Store purchases and Apple Music, and it is the native audio format across the entire Apple ecosystem.

Our converter typically performs a direct stream copy since MP4 already contains AAC audio in most cases. The video stream is stripped and the audio is repackaged with the .m4a extension — an operation that completes in seconds with zero quality loss.

M4A signals to operating systems and music players that the file is audio-only, which improves library organization and metadata handling. iTunes, Apple Music, and Finder display M4A files with album art, artist info, and chapter markers in ways that generic MP4 audio does not trigger. M4A also supports Apple's proprietary chapter and bookmark features, making it the right format for podcasts and audiobooks in the Apple ecosystem.

FFmpeg reads the MP4 container and copies the AAC audio stream directly into an M4A container using -c:a copy. The M4A file uses the same MPEG-4 Part 14 container as MP4 but sets the file type brand to M4A. Metadata (title, artist, album, year, track number, album art) is preserved or can be added during conversion. If the MP4 contains non-AAC audio, it is transcoded to AAC at 256 kbps. M4A supports both AAC-LC and HE-AAC profiles.