Resize an image by exact dimensions, by percentage, or to fit inside a maximum box — three different things people mean by "resize", rather than one width field and some mental arithmetic. Downscaling uses Lanczos resampling instead of the browser's built-in canvas scaling, which aliases badly the moment you shrink an image by more than half; on a 4000 pixel phone photo going down to 800, the difference is obvious. The aspect ratio is locked by default because distorting a photo is almost never intended, and "fit inside" never enlarges a small image. Export as PNG, JPEG or WEBP and see the resulting file size next to the original before you download. Your image never leaves your browser.
This tool does not use any data storage or network traffic.
Drop an image here, paste one, or .
PNG, JPEG, WEBP, GIF and AVIF, up to 50 MB. Nothing is uploaded.
Resize by
An image already smaller than this box is left exactly as it is — fitting never enlarges.
Format
Result
Why this looks better than a plain browser resize
Shrinking an image by drawing it into a smaller canvas — which is what most browser-based resizers do — uses a cheap filter that aliases badly once you go below about half the original size. Fine detail turns into jagged noise. This tool resamples with a Lanczos filter instead, which is what desktop image editors use, so a 4000 pixel photo scaled to 800 stays clean. It all happens on this page: your image is never uploaded, never stored, and reloading clears it.