Resize & Crop
Set exact pixel dimensions or draw a crop area and download results immediately.
Private & Secure
How it works
- 1
Your image is decoded into an ImageBitmap using the browser's native decoder inside a Web Worker.
- 2
For resize: the bitmap is drawn onto a new OffscreenCanvas at the target dimensions. drawImage() handles the bicubic-like scaling.
- 3
For crop: your drag selection is recorded in display pixels, then scaled back to original image coordinates using the display-to-source ratio.
- 4
The scaled source rectangle is passed as the source region in drawImage(), extracting exactly the cropped area into a new canvas.
- 5
The canvas is exported as a PNG blob and returned to the main thread for preview and download.
The crop coordinates are converted from screen pixels to source image pixels before processing, so the output is always at full resolution.