Free online W64 to M4A converter

Source format: W64

W64 is a Wave64 audio file format developed by Sony for storing uncompressed PCM audio in a structure similar to WAV, but with support for very large files beyond the 4 GB limit of classic RIFF/WAV. It is used mainly in professional audio production, recording, editing, and archiving, especially in workflows that need long recordings or high-resolution audio.

Because W64 is typically an uncompressed container, it preserves audio quality very well, but the files are usually large and not ideal for everyday playback on consumer devices.

Target format: M4A

M4A is an audio file extension commonly used for AAC or sometimes ALAC audio stored in an MP4 container. It is widely supported by phones, media players, streaming apps, and editing software. Compared with W64, M4A offers much smaller file sizes while keeping good perceived audio quality, especially when encoded with AAC.

Typical uses for M4A include music playback, podcast distribution, mobile storage, and sharing audio online. If you choose ALAC instead of AAC, you can keep lossless quality, though files will still be smaller than uncompressed W64 in many cases.

How to convert W64 to M4A

The best approach is to use a desktop audio tool such as FFmpeg or Audacity. If you want a simple command-line method, FFmpeg is usually the most reliable.

1. Install FFmpeg on your computer.
2. Open a terminal or command prompt in the folder containing your W64 file.
3. Run a command such as ffmpeg -i input.w64 -c:a aac -b:a 192k output.m4a.
4. Wait for the conversion to finish, then open output.m4a in your player to verify the result.

If you prefer a graphical workflow, you can use Audacity to open the W64 file and then export it as M4A through File → Export → Export Audio. Depending on your Audacity setup, you may need the appropriate AAC export support installed.

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

Notes on quality and compatibility

W64 to M4A is a lossy conversion if you encode to AAC, so some audio detail is discarded during compression. For speech, podcasts, and general listening, this is usually acceptable. For archiving or further editing, keep the original W64 file because repeated lossy conversions can reduce quality.

If you need maximum fidelity, consider exporting to ALAC in M4A instead of AAC, if your tools support it. Also note that some older players may handle AAC-in-M4A better than ALAC, while modern Apple devices and many media apps support both.

Because W64 is often used for large, high-resolution recordings, make sure the source file is not corrupted and that the sample rate and channel layout are preserved correctly during export. If the original audio is very long, conversion may take some time and the resulting M4A will be much smaller than the source.