Free online KUX to WAV converter

WAV is useful when audio from a downloaded Youku video must be edited in a DAW, imported into an audio editor, or archived as an uncompressed PCM file. KUX files usually contain video and audio in a proprietary Youku download format, so the conversion extracts the audio track rather than preserving the video.

What the KUX format is

KUX is a proprietary container associated with Youku, a Chinese video streaming service. Youku desktop software can create KUX files when videos are downloaded for offline playback. You may encounter them in a Youku download or cache folder instead of receiving a normal MP4 file.

KUX files can use proprietary packaging, segmentation, or encryption. Standard media players and FFmpeg may therefore reject some KUX files, even though the underlying content contains a conventional audio stream.

What the WAV format is

WAV is an audio container commonly used for uncompressed PCM audio. It is supported by DAWs, audio editors, video software, operating systems, and hardware recorders.

WAV avoids an additional lossy compression step when the source audio can be decoded. It is suitable for editing and production, but its files are much larger than MP3, AAC, or the audio track inside a KUX video. WAV does not contain the original video.

How to actually convert KUX to WAV

Convert it online

1. Open the free converter on 101convert.com.
2. Upload the KUX file.
3. Select WAV as the output format.
4. Start the conversion and download the resulting WAV file when processing finishes.

This is the simplest option when the KUX file is accepted by the converter and you do not want to install desktop software. Do not rename .kux to .mp4; changing the extension does not decode or convert the file.

Convert through an intermediate video file

If the KUX file is not recognized, use the Youku application or another KUX-compatible desktop converter to obtain an unencrypted MP4 or another standard video file first. Then extract its audio with FFmpeg:

ffmpeg -i input.mp4 -vn -c:a pcm_s16le output.wav

-vn discards the video stream, while pcm_s16le creates standard 16-bit little-endian PCM WAV audio. To preserve a higher-resolution decoded source, use an appropriate codec such as pcm_s24le instead.

In a graphical FFmpeg-based application, choose the source video, disable video output, select WAV or PCM audio, set the sample rate and channel layout if required, and export the file. FFmpeg generally cannot decrypt or interpret every KUX variant directly, so this command is intended for a standard intermediate file, not for an arbitrary KUX file.

Quality and compatibility limitations

Converting KUX audio to WAV does not improve its quality. If the original stream uses lossy AAC or another compressed codec, WAV only stores the decoded result without adding another lossy generation.

For general compatibility, use PCM WAV at 44.1 or 48 kHz and 16-bit depth. Some professional workflows require 24-bit WAV, but increasing the bit depth during conversion does not restore information already discarded by the source codec.

Check the output duration and listen for missing audio after conversion. A damaged, incomplete, or DRM-protected KUX download may fail even when other KUX files from the same source convert successfully.