How this video cropper works
Cropping a video means cutting away the edges of every frame so only a chosen rectangle remains. VimCut removes pixels from the sides or the top and bottom without scaling the rest, so the part that stays keeps its original resolution. You pick a shape such as Square 1:1 or Vertical 9:16, or draw a Custom box.
The preview shows what stays, and you can drag the box or its corner to move or resize it. The crop values are snapped to even pixel numbers, which the H.264 encoder requires. The video is re-encoded to an MP4 with H.264 video and AAC sound. When your browser supports it, the built-in hardware encoder is used. Otherwise it falls back to WebAssembly (ffmpeg.wasm). Cropping does not stretch the picture, so shapes in it are not distorted. A progress bar shows how far along the crop is.