Free online PARTIAL to MKV converter

What the PARTIAL format is

.partial is usually a temporary filename used by some browsers and download managers for an unfinished download. It is not a standardized video container, codec, or conversion format. The file may contain the beginning of an MKV, MP4, WebM, or another source file, and its contents cannot be identified reliably from the extension alone.

Resume or finish the download in the program that created the file. Closing that program, moving the temporary file, or renaming it can prevent automatic resumption. Common browser-specific alternatives include .part and .crdownload; all have the same basic limitation: they indicate download state rather than a playable media format.

What the MKV format is

MKV, formally Matroska Video, is a multimedia container that can hold video, multiple audio tracks, subtitles, chapters, attachments, and metadata in one file. It is useful for archiving and sharing video when several language tracks, subtitle streams, or chapter markers must remain together.

MKV does not specify a single video codec. H.264, H.265/HEVC, VP9, AV1, and other codecs may be stored inside it, so a device that supports MKV may still lack support for a particular embedded codec or audio format.

How to actually convert PARTIAL to MKV

1. Return the file to the browser or download manager that created it and resume the download. Wait until the application removes the temporary extension or reports completion.
2. Check the completed file with FFmpeg's probing tool:
   ffprobe -hide_banner completed_video
3. If FFprobe identifies valid streams and you only need an MKV container, remux without re-encoding:
   ffmpeg -i completed_video -map 0 -c copy output.mkv
   This preserves the original quality and is usually fast.
4. If the streams are unsupported by the target device, convert the video and audio instead:
   ffmpeg -i completed_video -map 0 -c:v libx264 -crf 20 -preset medium -c:a aac -b:a 192k output.mkv
   Remove -map 0 or add explicit stream mapping if the source contains unwanted data tracks or attachments.

You can also convert a completed, recognized media file on 101convert.com for free without installing software. Uploading a still-incomplete .partial file will generally fail because the converter cannot find the required container indexes or complete streams.

Quality, compatibility, and limitations

Renaming video.partial to video.mkv only works when the file was already a complete Matroska file whose extension was changed incorrectly; it does not convert or complete a download. A partial file may contain enough playable data for recovery, but FFmpeg cannot guarantee the missing end of the video, duration, subtitles, or index metadata.

Use -c copy when the completed source is already compatible with the intended player. Re-encoding with libx264 and aac improves compatibility but reduces quality and takes substantially longer. Keep the original completed download until the new MKV has been tested, because conversion cannot restore data that was never downloaded.