This chroma key video editor uses FFmpeg's RGB color-key filter in your browser. Pixels near the selected key color become transparent, while edge softness creates a gradual alpha transition around fine details. The final WebM uses VP8 because standard MP4 video does not carry transparency in this workflow.
The WebAssembly engine downloads only after you start an export. Encoding then runs locally in the current tab. A 60-second limit and device-aware file cap reduce the chance of exhausting browser memory.