If you calculate the size difference between JSON and a corresponding well-structured HTML/XML (i.e. without unnecessary nested divs), you will find that the ex

If you calculate the size difference between JSON and a corresponding well-structured HTML/XML (i.e. without unnecessary nested divs), you will find that the extra network overhead is negligible. Modern SPAs still require network calls for most meaningful interactions. We can use Ajax calls to fetch partial HTMLs and replace target elements (like HTMX does).