No upload, 100% local, no account

Crop video

Crop to a ratio preset (1:1, 16:9, 9:16, 4:3, 3:4) or an exact rectangle. Everything runs in your browser; your file never leaves your device.

How Crop video works

Crop video trims the frame down to the part you want to keep, turn a landscape clip into a 1:1 square for Instagram, a 9:16 vertical for Reels and TikTok, or cut to an exact pixel rectangle. Pick a centred ratio preset (1:1, 16:9, 9:16, 4:3, 3:4) or type in a manual rectangle, then download the result.

It runs through ffmpeg (the `crop` filter) compiled to WebAssembly. Because cropping changes the frame size, the video is re-encoded with H.264 while the audio is copied untouched. No account, no watermark.

Frequently asked questions

Are my files uploaded to a server?

No. ffmpeg compiled to WebAssembly crops your video in this browser tab, it is read into memory on your own device and the crop filter cuts the chosen rectangle there (crop=W:H:X:Y, or a centred ratio crop), re-encoded with libx264, and the result is offered as a local download. Nothing reaches Sunasty or any third party. Open your browser's DevTools, go to the Network tab and watch: no request carries your video.

What aspect ratios can I crop to?

The presets are 1:1 (square), 16:9 (landscape), 9:16 (vertical), 4:3 and 3:4. Each one crops the centre of the frame to that shape, whatever your source resolution is. For anything else, switch to manual mode and enter an exact width, height and offset in pixels.

Does cropping reduce quality?

Cropping itself removes pixels around the edges; the kept area is re-encoded with H.264 at a high quality, so any quality loss is minor. The audio track is copied without re-encoding.

Does it work offline?

Yes, once the page has loaded. Because the processing happens on your device, you can disconnect from the network and the tool keeps working. This is the clearest proof that your data never leaves your machine.

Is it free? Do I need an account?

It is completely free and requires no sign-up. There are no watermarks, no daily limits and no tracking cookies needed to use the tool.