Free online PPSX to MKV converter

Some video players and editing workflows accept MKV but cannot open a PowerPoint slideshow. Converting a PPSX creates a video that can be played or edited as footage, rather than a presentation that needs PowerPoint-compatible software.

What the PPSX format is

PPSX is the PowerPoint Open XML slide-show format, used for presentations that open directly in slide-show mode. Microsoft PowerPoint creates it; it is also encountered when someone shares a finished presentation instead of a file intended for editing. A PPSX contains slides and may include transitions, animations, audio, and video, but it is not itself a video file.

What the MKV format is

MKV (Matroska Video) is a multimedia container that can hold video, audio, subtitles, and chapters in one file. It supports a range of codecs and is useful for playback, editing, or archiving when the target software or device supports Matroska. Compatibility depends on the player and the codecs inside the MKV, not just the filename extension.

How to convert PPSX to MKV

Online on 101convert.com

1. Open the PPSX-to-MKV converter page on 101convert.com and upload the presentation. The page allows batch conversion; each file is subject to the size limit shown there.
2. Set show each page for to choose how long each slide appears.
3. Start the conversion, then download the resulting MKV file or files.

Offline with desktop software

LibreOffice Impress and FFmpeg are free, cross-platform options for Windows, macOS, and Linux. In Impress, open the PPSX and use File → Export to export the slides as numbered PNG images. This image-based route makes a video from still slides; it does not retain PowerPoint animations, transitions, or embedded audio.

With images named sequentially, such as slide-1.png, slide-2.png, run this in the folder containing them to show each slide for five seconds:

ffmpeg -framerate 1/5 -i slide-%d.png -c:v libx264 -pix_fmt yuv420p slideshow.mkv

Microsoft PowerPoint can render a presentation as a video, preserving supported animations, transitions, and recorded timings. Use File → Export → Create a Video and save the result as MP4. Then use FFmpeg to place the MP4 streams in an MKV container without re-encoding:

ffmpeg -i presentation.mp4 -c copy presentation.mkv

Quality and limitations

The LibreOffice image sequence has no slide motion effects or audio; the FFmpeg command sets a fixed five-second duration per image. PowerPoint's video export is preferable when the presentation relies on animations, narration, or slide timings. The stream-copy command keeps the original audio and video encoding, so it is fast and does not reduce quality, but it cannot fix codecs that a target player does not support.