How to Resize an Image (Without Losing Quality)
Resizing changes an image's pixel dimensions. Learn about aspect ratio, upscaling vs downscaling, and how to resize images privately in your browser.
Resizing an image changes its width and height in pixels — to fit a layout, meet an upload limit, or reduce file size. The key is to keep the aspect ratio so the image is not stretched.
Keep the aspect ratio
Aspect ratio is the relationship between width and height. Lock it when resizing so a 1600×900 photo scales to 800×450, not 800×900 (which would squash it). Most tools link the two dimensions by default.
Downscaling vs upscaling
- Downscaling (making smaller) is safe — the image stays sharp.
- Upscaling (making larger) invents pixels that were never captured, so it looks soft or blocky. Start from the highest-resolution original you have.
Resize vs compress
Resizing changes dimensions; compressing reduces file size at the same dimensions. For a smaller file, resize to the size you actually display, then compress.
Resize now
Set exact dimensions in the image resizer, all in your browser. To shrink the file further, see How to compress images for the web.