Choose Wix for an all-in-one ecosystem
It is a strong fit when you want the editor, apps, hosting, and support to stay inside one platform and you are comfortable keeping the finished site there.
Wix explicitly says the content you create belongs to you. It also says the finished Wix site relies on proprietary services and must operate on Wix servers. That distinction matters: owning your words and images does not automatically mean you can lift the complete working site and place it on another host.
Squarespace provides a WordPress-format export for compatible content, including many standard pages and one blog. Its own documentation lists items that do not export, including various page types, product and video blocks, style settings, and custom CSS. A move is possible, but it can become a partial migration followed by a rebuild.
A portable-code approach starts from a different premise. The host is a service, not the only environment where the site can exist. That does not eliminate migration work—domains, forms, databases, and third-party services still need care—but it preserves the core page code and reduces the chance that leaving means starting over.
Do not confuse domain ownership with website portability.You can often move a domain away from a platform even when the site built on that platform cannot be moved intact.