rsz.app

I built rsz.app after yet another week of doing the same annoying thing over and over: taking one good product photo and manually cropping it into different sizes for Shopify, Amazon, ads, and social. Every platform wanted a slightly different ratio, and every tool I tried either stretched the image, chopped off the product, or left ugly padding around it. The problem I wanted to solve was simple: upload an image once, tell the tool which sizes you need, and get back clean results that actually respect the subject of the photo. No guessing, no “center crop and hope for the best,” and no generative backgrounds that might break brand guidelines. Just smart resizing that understands where the product, face, or logo is and keeps it safe in the frame. The first version was honestly just a basic batch resizer I used myself. As I used it on real catalogs, I kept hitting edge cases, so the approach evolved a lot. I added subject detection so important parts of the image stay in view, then presets for common marketplaces and social formats instead of making people type dimensions by hand. When a few teams started asking if they could plug it into their own pipelines, I realized it needed to be more than a little tool, so I focused on the API and batch processing. So rsz.app grew from a personal “I am tired of doing this in Photoshop” script into a proper product for anyone who has to handle a lot of images and wants them to look right everywhere without babysitting every single crop.