MP4 to MKV

Repackage MP4 into flexible MKV—keep every track with zero quality loss.

or drag & drop up to 100 MB here

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How to convert MP4 to MKV online

Click "Choose files" or drag a video onto the page. We handle HD and 4K clips up to 100 MB over encrypted HTTPS.

MKV is pre-selected for lossless remuxing. Keep every subtitle and audio track, or deselect the ones you don’t need.

Press “Convert”. In seconds your new .mkv file is ready—no quality loss, perfect for Plex, VLC, or backups.

MKV supports multiple audio streams, soft subtitles, chapter markers, and advanced codecs, making it ideal for archiving or media servers.

By default we perform a lossless remux—no re-encoding—so quality and bitrate stay identical to the source MP4.

Not yet. The current version keeps existing subtitle tracks but doesn’t embed new ones; you can add them later with tools like MKVToolNix.

Most modern smart TVs, media boxes (Roku, Fire TV), and players like VLC and Plex handle MKV. Older devices may require MP4.

You can upload videos up to 100 MB. Files larger than 100 MB cannot be processed.

All transfers use HTTPS. Files are processed only in volatile memory and are automatically deleted minutes after conversion.

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