Free online KUX to TS converter

Some video players, broadcast tools, and media-processing workflows require an MPEG transport stream instead of Youku's proprietary KUX container. Converting the file produces a standard .ts file for compatible playback, multiplexing, or archival workflows.

What the KUX format is

KUX is a proprietary video container associated mainly with Youku downloads and its desktop software. Youku may split a download into multiple segments, and some KUX files include protection or encoding that general-purpose media applications cannot read directly. The extension identifies the container, not a universally supported codec.

KUX files are commonly encountered after saving videos through Youku rather than through a standard browser download. Renaming .kux to .ts does not convert the container or remove any protection.

What the TS format is

TS, or MPEG transport stream, is a packetized container designed for continuous delivery, digital television, broadcast systems, and error-tolerant playback. It commonly carries H.264 or H.265 video with AAC, MPEG audio, or other broadcast-compatible streams.

TS is useful when a hardware player, video editor, IPTV system, or processing application explicitly requires MPEG-TS. It can contain multiple audio or subtitle streams, but compatibility depends on the codecs and stream layout inside the file.

How to actually convert KUX to TS

The simplest method is the free converter on 101convert.com, which runs in a browser without installing software:

1. Open the KUX-to-TS converter on 101convert.com.
2. Select the source .kux file.
3. Choose TS as the output format and start conversion.
4. Download the resulting .ts file after processing finishes.

For a locally readable KUX file, FFmpeg can attempt a stream copy, which avoids re-encoding:

ffmpeg -i input.kux -map 0 -c copy -f mpegts output.ts

If FFmpeg reports an unknown format, invalid data, or decoding errors, the file likely uses a KUX variant or protection that the standard build cannot decode. A successful stream copy preserves the original encoded quality; it changes the container rather than improving or reducing the video.

Quality and compatibility limitations

Conversion cannot recover quality already lost in the source. A TS file may be larger than the original KUX because TS has more packet and continuity overhead, and the output may retain codec parameters that a particular player does not support.

If stream copying produces an unusable file, decoding and re-encoding may be required, but only after the KUX content can be read. For H.264 video with AAC audio, a broadly compatible fallback is:

ffmpeg -i input.kux -c:v libx264 -c:a aac -f mpegts output.ts

Protected or incomplete Youku downloads may not be convertible by ordinary desktop software. Use a complete file obtained through an authorized Youku download method, and verify the output by opening it in the target application rather than relying only on the .ts extension.