Crop an Image Online

How it works

The selection is stored as four numbers in the image's own coordinate system: left, top, width, height. The preview is drawn at whatever scale fits your screen, and every pointer movement is divided by that scale before it changes the rectangle. Keeping the crop in image pixels rather than screen pixels is what makes the exported region exact — a preview scaled to 18 percent of a large photo would otherwise quietly turn a full-resolution crop into a small one.

Handle dragging works by converting the rectangle into two opposite edges, applying the movement to whichever edges the handle touches, and rebuilding. That sounds like a detail, but it is what makes dragging the right handle leftwards past the left edge behave sensibly: the edges swap and you get a valid rectangle, rather than a negative width and an invisible selection.

With a ratio locked, one axis leads and the other is derived. Corner and horizontal handles drive from the width; top and bottom handles drive from the height. The rectangle is then re-anchored to the edge you were not dragging, so the opposite corner stays pinned instead of the whole box drifting across the image as you resize.

The export itself draws the selected source region into a canvas of exactly that size and encodes it. There is no scaling step, so the pixels you selected are the pixels you get.

When you'd use this

Profile pictures and avatars are the most frequent case, because almost every platform wants a square and almost no camera produces one. Locking the square preset and dragging up to center a face takes seconds.

Social formats are the second. Stories and reels want 9:16, feed posts often want 4:5, video thumbnails want 16:9. Cropping to the right shape yourself gives you control over what gets cut; letting the platform crop automatically usually means the top of someone's head disappears.

Removing surroundings is the third and least glamorous: trimming a screenshot down to the relevant panel, cutting the edge of a desk out of a product photo, or straightening the framing of a document photographed at arm's length. All of it is faster than opening an image editor for one operation.

Cropping versus resizing

These are different operations that are easy to confuse, and the difference matters when a platform gives you a required size.

Cropping changes which part of the image you keep. The remaining pixels are untouched, and the output dimensions are however large that region happens to be.

Resizing changes how many pixels the image has. Everything stays in frame and each pixel is recalculated from its neighbors.

A requirement like "1080 by 1080" usually needs both: crop to a square so nothing is distorted, then resize that square to 1080. Doing only the second would squash a rectangular photo into a square, which is the error that produces the stretched-looking profile pictures you see everywhere.