How to resize an image without losing quality
Resizing down and resizing up behave very differently, and understanding which one you're doing sets the right expectations.
Making an image smaller
This is safe — you're using fewer of the pixels that were already there, so the result stays sharp. Open the Image Editor, set your target dimensions, and download.
Making an image larger
Enlarging has to invent pixel data that was never captured, which is why upscaled images often look soft. There's no way to fully avoid this, though Image Enhancer can improve the result somewhat compared to a basic resize.
Keeping proportions correct
Always keep the aspect ratio locked when resizing unless you specifically want to stretch the image — an unlocked resize distorts faces and objects noticeably. The Aspect Ratio Calculator helps work out matching dimensions.
A practical rule of thumb
Always start from the largest, highest-quality version of an image you have access to, and resize down from there for each specific use — rather than resizing once to a medium size and then trying to resize that copy up again later for a different purpose.
Resizing for a website
Match the image dimensions to the size it will actually display at on the page — an image shown at 800 pixels wide gains nothing from being 4000 pixels in the file, only extra load time. See Image Compress for shrinking the file size once the dimensions are right.
Batch resizing many images consistently
When preparing many images for the same purpose — a product catalogue, for instance — resize them all to the exact same dimensions rather than similar-but-different sizes, since consistency across a set matters more for a professional look than any single image being perfectly sized.
