What cropping a video means
Cropping a video removes pixels from the edges of every frame, so the picture that remains is smaller in width and height. It is different from trimming, which shortens the clip in time, and different from resizing, which keeps the whole picture but shrinks or enlarges it. A crop permanently discards the outer part of the frame.
Because the frame changes, a video cannot simply be copied as it is. Every frame has to be decoded, cut down, and encoded again. That re-encoding step is why cropping takes noticeably longer than operations that only rearrange existing data.
This tool uses ffmpeg compiled to WebAssembly, so the decoding and encoding happen inside your browser tab instead of on a server.
When a crop is useful
People usually crop video to get rid of something at the edge of the picture: a dark border left over from a screen recording, a stray object near the side of a shot, or a bit of empty space around the subject. A tighter crop can also make a shot feel closer to the subject.
It is also a quick way to cut away a distracting corner without opening a full editor. If the unwanted area is only a thin strip, a small crop is often enough.
One thing to know before you start: this tool does not let you choose the crop area. It applies one fixed crop, described in the steps below. If you need a specific region or aspect ratio, this is not the right tool for that job.
How to crop a video with this tool
- Drop a video file onto the upload area, or click it to choose one. Any file your browser reports as video is accepted.
- The file name and size are shown. There are no crop controls, because the crop is fixed.
- Click Run. On first use the video engine downloads (roughly 30MB) and is cached afterward. A progress bar shows while it works.
- The tool keeps the center of the frame and removes the outer edges so that the result is 80% of the original width and 80% of the original height. For a 1920 by 1080 video that is 1536 by 864.
- Watch the result in the preview player below the options.
- Click Download. The file is saved as your original name followed by
-crop, as an MP4.
Use Start over to clear the file and try another one.
Limits and tips
The fixed crop is centered, so it trims all four edges equally. It cannot remove only the top bar or only the right side. If your unwanted area sits on one side, a centered crop may cut away good picture on the other sides and still leave some of the unwanted part.
The output is always an MP4 and the video is re-encoded with the engine's default settings. There is no quality slider, so file size and quality follow those defaults. Because it re-encodes, long or high-resolution files can take a while, and the work uses your device's memory. If the tool shows an error, the file may be too large for the browser to handle, or its dimensions may not suit the encoder. Trying a shorter or smaller clip is the simplest next step.
Cropping twice compounds the loss in both size and quality, so keep your original file. If you also want to shorten the clip first, the Trim Video tool can do that, and the Change Resolution tool can scale the result afterward.