Convert QT to MKV — Free Online Converter

MKV (Matroska Video) is an open-source container format that can hold virtually unlimited numbers of video, audio, subtitle, and metadata tracks in a single file. Named after Russian matryoshka nesting dolls, it's the most flexible multimedia container available. Converting QT to MKV moves content from Apple's proprietary container into an open standard that excels at preserving complex multimedia structures without codec transcoding.

MKV accepts nearly every codec in existence, meaning QT content can often be remuxed (repackaged without re-encoding) for zero quality loss and near-instant conversion. MKV also supports unlimited subtitle tracks, multiple audio languages, chapter markers, and rich metadata — features that QT handles inconsistently. For archival and multi-language content, MKV is the superior container.

FFmpeg remuxes the QT content into Matroska's EBML (Extensible Binary Meta Language) structure. If the QT video uses H.264 or HEVC, the video stream is usually copied directly without re-encoding. ProRes and other less common codecs can also be stored in MKV but may require compatible decoders. Audio streams are typically copied as-is. Multiple tracks and chapters are mapped from QT atoms to MKV elements.