The verdict
For a creator or small team selling a few digital products to an existing audience, I'd pick Sellfy. You can be live in an afternoon and file delivery is handled. If you sell physical products, need stock and shipping rules, want several sales channels or want tools such as Klaviyo and Gorgias to plug in, I'd pick Shopify. Watch the cost on both sides. Sellfy plans are capped by annual sales volume, so check where each tier ends. Shopify's bill grows with apps, themes and payment fees. If the catalogue will grow, start on Shopify. Moving off either one later is real work, because customers, products and order history live inside the platform.