How it works
When you load the image, the width and height fields are pre-filled with its original dimensions. With "Keep aspect ratio" checked, changing one field automatically adjusts the other so the image is not distorted; uncheck it to stretch/squash freely. Everything is processed locally, redrawing the image on an HTML5 canvas at the new size.
Frequently asked questions
Is my image uploaded to a server?
No — resizing happens entirely in your browser. Your image never leaves your computer.
Does making it bigger reduce quality?
Yes — increasing dimensions beyond the original size stretches the existing pixels, which can make the image look blurry. Reducing dimensions does not have this problem.
What happens if I uncheck "Keep aspect ratio"?
The image will be stretched or squashed to fit exactly the width and height you entered, even if that distorts the original proportions.