Ecwid by Lightspeed

Ecwid solves a problem the rest of this category tends to ignore: a business already has a website it is happy with, and now needs to sell something. Rather than requiring a move, it embeds a working store into the site that exists, and keeps one inventory behind however many places the products appear.

That embedding is the entire design. The catalogue, cart and checkout are hosted by Ecwid and rendered inside the host page, so the surrounding site keeps its design, its address and its content, and the store can be added to a second site or a social channel without duplicating the products.

The catch is that a bolt-on is what it stays. The storefront's appearance is constrained by being a component rather than the page, the cheapest plan allows only a handful of products and no custom domain of its own, and the tier that lifts those limits costs more than several complete platforms. It earns its place when keeping the existing site matters more than anything else, and struggles to justify itself when it does not.