Image resizer
Change the pixel size of a picture by width, height, percentage or a bounding box, keeping the proportions.
Image resizer
Pick a picture, choose how to resize it and press Resize. You can set a width and let the height follow, set a height, scale by a percentage, fit the picture inside a box such as 1920 by 1080, or force an exact size. The page shows the new dimensions and megapixels before you commit, then draws the image at that size and offers it as a download.
The aspect ratio is kept in every mode except Exact size, so a 4000 by 3000 photo fitted into 1920 by 1080 becomes 1440 by 1080 rather than being squashed. Enlarging is off by default. Stretching a small image to a larger size invents no detail and only makes the file bigger, so a request larger than the original is held at the original unless you tick Allow enlarging. The longest side is limited to 16384 pixels, the most a browser canvas can draw.
Resizing is the most effective way to cut a file size. Halving both dimensions leaves a quarter of the pixels, which usually saves far more than lowering the quality. For web pages, sizes of 1200 to 2000 pixels on the long edge are typical, and social networks and marketplaces publish their own limits. Choose WebP or JPEG and the quality slider for photos, or PNG when you need lossless output with transparency. After resizing you can run the result through the image compressor for a smaller file.
Your picture stays on your device: it is decoded, redrawn and saved in the browser with no upload, no queue and no size quota. The same page works as a plain calculator too. Type a size such as 4000x3000 and it tells you the new dimensions for the options you chose, without any file at all.