Image Resizer & Cropper

Resize an image to exact pixel dimensions or to a percentage of its current size. Choose how it should handle a box that is a different shape from the image — fit inside it, fill and crop, or stretch.

Scaling uses high-quality resampling rather than dropping pixels, so downscaled photographs stay sharp instead of going blocky.

How it works

Resizing is two decisions, and most tools only let you make one. The first is the target size. The second — the one that actually matters — is what happens when the target is a different shape from your image.

Fit scales until the whole image sits inside the box. Nothing is lost and nothing is distorted, but the result is usually not the exact size you asked for: a 3:2 photo fitted into a square box comes out square-ish on one axis only. Use it when losing part of the picture is unacceptable.

Fill and crop scales until the box is completely covered, then trims the overflow from the edges, centred. The result is exactly the size you asked for and the aspect ratio is intact, at the cost of losing the edges. This is what you want for thumbnails and avatars — and the reason to check the result, because a centred crop of a group photo removes the people on the ends.

Stretch forces both dimensions and distorts the picture. It is almost never what you want; it is here because occasionally a specification demands exact dimensions from a non-matching source.

On quality: this uses bicubic resampling, which averages the source pixels contributing to each output pixel. The cheap alternative — nearest neighbour — just picks one pixel and discards the rest, which is why images downscaled by naive tools look noisy and aliased. Enlarging is a different matter entirely: no amount of resampling invents detail that was never captured, so scaling up past about 150% always looks soft. Start from a larger original if you can.

One practical note for the web. Do not upload a 4000-pixel photo and resize it in CSS — the browser downloads every one of those bytes before shrinking it on screen. Resize to roughly the size it will actually be displayed at, allowing perhaps 2× for high-density screens, and serve that.

Frequently asked questions