Trimming is essential for highlights, lessons, and social clips. MBox shows a visual timeline — drag handles to set your range precisely. In Keep Selected mode, the FFmpeg engine can stream-copy when possible, skipping re-encode for speed and no quality loss. WebCodecs is great when you want fast preview-driven edits. Preview on the left before export, then download in one click — perfect for meeting recordings, course segments, or short-form content.