Trim Video Borders

About Trim Video Borders

Unwanted borders around a video's actual content — black bars from a mismatched aspect ratio, a recording that captured more of the surroundings than intended, or just wanting to zoom in slightly on the frame — call for cropping rather than resizing, since cropping removes pixels rather than scaling them down. This tool trims an equal percentage off all four sides, centered on the frame.

A real FFmpeg build compiled to WebAssembly performs the crop entirely inside your browser using the crop filter, computing exact pixel dimensions from your chosen percentage relative to the video's actual width and height — this means the same percentage setting scales correctly whether your source video is a small phone recording or a large 4K file.

Because cropping requires re-encoding (the crop filter changes every frame's actual pixel content, unlike operations that can stream-copy), the video is fully re-encoded to H.264 during processing — the audio track is copied through unchanged, since audio isn't affected by a visual crop.

The crop is always centered and symmetric across all four sides — for asymmetric cropping (removing more from one side than another, or targeting a very specific region), a more advanced video editor with manual crop-box positioning would be needed instead.

How it works

1. Upload your video. The file loads into the browser-based FFmpeg engine.
2. Set the crop margin. Choose what percentage to trim from each side.
3. Crop and download. A centered crop is re-encoded and ready to save.