Scale an image to exact pixel dimensions or by percentage, with the aspect ratio locked by default. 100% browser-side — nothing is uploaded.
Scaling down is effectively lossless to the eye — the browser uses high-quality resampling. Scaling up cannot invent detail, so enlarging past the original dimensions always looks softer.
Leave "Keep aspect ratio" checked and set only the width — the height is calculated for you. Uncheck it only when you deliberately need to distort the image to fixed dimensions.
1920 px wide covers full-width hero images on Full HD screens, 1280 px suits in-article images, and 800 px is plenty for thumbnails and previews. All three are one-click presets here.
This tool handles one image at a time so you can verify each result. For shrinking a whole batch, use Compress Image, which processes multiple files in one pass.