Image Resizer

Resizing changes the pixel dimensions of an image by redrawing it onto a canvas set to your target width and height, letting the browser's image scaling handle the interpolation between the original and new pixel grid. Uploading a file detects its natural dimensions automatically and pre-fills the width and height fields, so you always start from the source size rather than an arbitrary default.

The aspect ratio lock keeps width and height proportional to each other as you type: changing one field recalculates the other using the image's original width-to-height ratio, which avoids the stretching or squashing that happens when the two dimensions are set independently. You can uncheck the lock if you deliberately want a different aspect ratio, though that will distort the image relative to the source.

Unlike cropping, resizing doesn't discard any part of the image — it maps every pixel of the original onto the new grid, so shrinking loses fine detail (downsampling averages pixels together) while enlarging beyond the original resolution introduces blur rather than genuine new detail. The output downloads as a PNG at exactly the dimensions you specified.

Resizing redraws the image on a canvas at the new size, and the browser interpolates between the old and new pixel grids. Shrinking an image is safe. Enlarging adds no real detail, so enlarged photos look soft.

For web use, serve images at roughly the size they are displayed, doubled for high-density screens. Oversized images slow pages and hurt Core Web Vitals scores.