Image Resizer

Resizing changes how many pixels an image contains. Compression keeps the pixel dimensions and reduces the file size by storing those pixels more efficiently. The distinction matters because resizing is usually the bigger win: a 4000 × 3000 photo holds twelve million pixels, and a layout slot 800 pixels wide can only ever show a fraction of them. The rest is weight your visitors download for nothing.

The practical order is resize first, then compress. Scale to the largest size the image will genuinely be displayed at, then apply compression to reach a target file size. Pixels you have already removed cost nothing to compress, so the two steps together reach a far smaller file than either one alone.

With the aspect ratio locked, entering one dimension fills in the other automatically and the image keeps its original proportions. This is what you want almost all of the time — unlocking the ratio and forcing both numbers stretches or squashes the picture, which is immediately obvious on faces, circles, and text.

When a form demands exact dimensions that do not match your image's proportions, resize with the ratio locked to fit inside the target box, then crop the remainder to the precise size. That keeps everything in proportion while still hitting the required numbers.

Scaling down is straightforward: many pixels are averaged into fewer, and with good resampling the result often looks sharper than the original at that size. This tool uses Lanczos resampling, which preserves edge detail noticeably better than the nearest-neighbour or bilinear methods built into older software.

Scaling up is a different matter. Enlarging cannot invent detail that was never captured, so a small image blown up will look soft no matter which algorithm is used. Modest increases of 10–25% hold up well; beyond that, softness becomes visible. Where possible, start from the largest original you have.

Social platforms and marketplaces are strict about dimensions. Square 640 × 640 and 1080 × 1080 suit product grids and Instagram posts, 1200 × 630 is the standard link preview size, and 1920 × 1080 covers full-screen backgrounds. Government and exam portals typically specify something much smaller, often around 200 × 230 pixels for photographs.

Everything happens inside your browser for this tool — the image is resized locally using WebAssembly and never uploaded, so it also works offline once the page has loaded.