Free online M4A to W64 converter

Source format overview

M4A is an audio container format commonly used for compressed audio, usually with AAC or sometimes ALAC encoding. It is widely used by Apple devices and software, as well as many media players and audio tools. Typical uses include music downloads, voice recordings, podcasts, and general audio distribution where smaller file size matters.

Target format overview

W64 is a Wave64 audio file format developed by Sony as an extension of the standard WAV format. Its main advantage is support for very large audio files beyond the 4 GB limit of classic WAV. It is used in professional audio workflows, long recordings, multichannel projects, and archival tasks where a large, uncompressed PCM container is needed.

How to perform the conversion

The most reliable way to convert M4A to W64 is with FFmpeg, because it supports both formats and gives precise control over the output codec. Since W64 is typically used for uncompressed PCM audio, the conversion usually means decoding the M4A audio and writing it into a Wave64 container.

1. Install FFmpeg if it is not already available on your system.
2. Open a terminal or command prompt in the folder containing your .m4a file.
3. Run a command such as ffmpeg -i input.m4a -c:a pcm_s24le output.w64.
4. If you need standard 16-bit audio instead, use ffmpeg -i input.m4a -c:a pcm_s16le output.w64.
5. Check the resulting file in an audio editor or player that supports W64.

If you prefer a graphical workflow, Audacity can open many M4A files through its import support and export to Wave64 when the required codecs are available. In Audacity, open the file, then choose File → Export → Export Audio and select W64 or a Wave64-compatible WAV variant if offered by your version and installed libraries.

You can also convert the file on 101convert.com for free, without installing any software.

Quality and compatibility notes

M4A is usually compressed, so converting it to W64 does not restore lost audio detail; it only places the decoded audio into a larger, uncompressed container. For that reason, the output may be much larger than the source file.

Because W64 is less common than WAV, some consumer players and editors may not open it. It is best suited for professional audio software and archival use. If compatibility is more important than large-file support, standard WAV may be a better choice. Also note that if the source M4A contains AAC audio, the conversion is a decode-and-rewrite process, so the output quality depends entirely on the original file.