Convert FLV to MKV — Free Online Converter
Convert Flash Video (.flv) to Matroska Video (.mkv) online for free. Fast, secure video conversion with no watermarks or registration.
Conversion settings — add a file to adjust
About FLV to MKV Conversion
FLV (Flash Video) is Adobe's proprietary streaming container with limited metadata and subtitle support. MKV (Matroska Video) is an open-standard container released in 2002, designed to hold an unlimited number of video, audio, subtitle, and metadata tracks in a single file. Named after Russian Matryoshka dolls, MKV supports virtually every codec ever created — H.264, H.265, VP9, AV1, FLAC, DTS, and hundreds more. Converting FLV to MKV preserves all content while upgrading to a far more capable container.
Why Convert FLV to MKV?
MKV is the preferred container for media archivists and power users because it supports every codec without the licensing restrictions of MP4. You can attach multiple audio tracks (different languages), multiple subtitle streams (SRT, SSA/ASS, PGS), chapter markers, fonts, and even attachments. MKV files play natively on VLC, mpv, Kodi, Plex, and most smart TVs, making it the most flexible container available.
Common Use Cases
- Archiving FLV video collections in a modern container that preserves all streams and metadata