Convert WebM video to MKV in a browser-only batch. Files, streams, metadata, and results are never uploaded.
Files stay in this browser tab and are never uploaded. Up to 250.0 MiB per file and 10 files.
Lower CRF values preserve more detail and usually create larger files.
The private batch workspace is ready. Video encoding becomes available after the verified browser engine is loaded.
WebM probe and decode → stream-aware conversion → MKV verify
WebM input accepts approved VP8, VP9, or input-only AV1 profiles with compatible WebM streams.
MKV output uses VP9 and Opus with compatible Matroska chapters and text subtitles.