Why PNG at 500KB? Product image uploads for e-commerce sellers
Amazon Seller Central and Flipkart Seller Hub both accept PNG product images up to 500 KB before triggering their re-encoding pipeline. Going in at 500 KB or lower keeps your original alpha channel intact — crucial for products photographed on transparent backgrounds. Etsy's listing image endpoint accepts up to 5 MB but re-encodes anything over ~600 KB.