Convert CRDOWNLOAD to MKV

A media server, editor, or archive workflow may require an MKV file, while a .crdownload file usually indicates that the source download is unfinished. Complete or verify the download before remuxing it; changing the suffix alone does not convert video.

What CRDOWNLOAD files are

.crdownload is a temporary download suffix used by Google Chrome and other Chromium-based browsers, including Microsoft Edge, Brave, and Opera. During a download, a file may be named movie.mkv.crdownload; the browser normally removes .crdownload after it has received the complete file.

The suffix is not a media format. A CRDOWNLOAD file may contain part or all of an MKV, MP4, WebM, ZIP archive, installer, document, or another file type. A cancelled download, network interruption, browser crash, or unavailable source can leave it incomplete.

Open the browser download list and resume or restart the download first. In Chrome, use Menu → Downloads or open chrome://downloads. If the download cannot be resumed, keep the original CRDOWNLOAD file unchanged and test a copy.

What MKV files are

MKV is the filename extension for Matroska, a multimedia container format. It can hold video, multiple audio tracks, subtitle tracks, chapters, attachments, and metadata in one file, making it useful for preserving multi-track video and subtitles.

MKV is not a video codec. It can contain H.264, H.265/HEVC, AV1, VP9, AAC, Opus, AC-3, DTS, and many other stream types. The target player must support both the MKV container and the codecs inside it; older TVs, phones, and editors often support MP4 with H.264 and AAC more reliably.

Check the incomplete download

If the expected file was film.mp4 and the browser left film.mp4.crdownload, copy the file and rename the copy to film.mp4. This only restores the expected extension for testing; it does not repair missing data. Test the copy in VLC Media Player or inspect it with FFmpeg:

ffprobe -hide_banner "film.mp4.crdownload"

If the original filename or type is unknown, inspect the download URL or browser download entry before renaming it. Do not assume every CRDOWNLOAD file is video.

A partial MKV may play until the missing point because Matroska can be read progressively. A partial MP4 often fails completely because its index metadata may be stored near the end of the file. Errors such as moov atom not found, Invalid data found when processing input, truncated packets, or missing streams indicate that conversion cannot restore the absent content.

Remux a complete media file to MKV

For a complete, readable media file, FFmpeg can copy its existing streams into an MKV container without re-encoding:

ffmpeg -i "film.mp4" -map 0 -c copy "film.mkv"

-c copy remuxes the streams, so it is fast, causes no generation loss, and usually changes file size very little. Use the CRDOWNLOAD file as the input only if FFprobe recognizes it as complete enough to read; otherwise resume or download the original file again.

MKVToolNix GUI is a desktop alternative for remuxing. Open Multiplexer → Add source files, select the completed source file, choose the required video, audio, and subtitle tracks, set an output filename ending in .mkv, and select Start multiplexing. MKVToolNix copies compatible streams but cannot repair corrupt or absent data.

Re-encode only when required

Use HandBrake when the target device cannot decode the source codecs or when a smaller file is required. Open the completed source, select Summary → Format → MKV, choose a supported encoder such as H.264 or H.265, configure audio and subtitle tracks, then select Start Encode.

Re-encoding takes longer than remuxing and can reduce quality. Use FFmpeg or MKVToolNix when the existing codecs already meet the playback requirements.

Online conversion and compatibility limits

CloudConvert is suitable for a completed, non-sensitive file when desktop software is unavailable. Rename a verified file to its known original extension before upload if the browser left the temporary suffix. Online services cannot reconstruct an incomplete download, and uploading private video gives a third party a copy of the file.

Converting a container does not improve resolution, remove DRM, repair corruption, or guarantee playback. If a media server or device rejects the finished MKV, check its accepted video, audio, subtitle, and container formats; remuxing will not help when the device cannot decode the existing streams.