Client-Side Rendering (CSR)

In client-side rendering the server hands over an almost empty HTML file (one 'div id=root' and a script tag) and the browser does the rest: download the JavaScript, run it, fetch the data, build the DOM. This is what a plain Vite or Create React App build does. Do not confuse it with client-side navigation: a router swapping views without a full reload is a navigation model, and the views it swaps in can be built in the browser, streamed from the server, or a mix, depending on the framework.

Reach for it when the content is private, personal, or highly interactive: dashboards, editors, admin panels, anything behind a login. There is no SEO to lose, and a build cannot pre-render a page that depends on who is looking at it. Logged-in pages can still be worth server-rendering, though: it paints sooner on a slow phone and degrades better when the bundle fails, so treat it as a real tradeoff (simpler hosting and simpler code against a faster, sturdier first paint) rather than a rule that private means client-rendered. Navigation after boot feels quick either way, because the router usually avoids fetching a whole new document.

The gotcha is the first paint. Nothing at all is visible until the bundle downloads, parses, and runs, so slow phones and slow networks stare at white. Code-split per route, ship a real skeleton instead of a spinner, and never CSR a marketing page you want ranked: crawlers and link previews often see the empty shell.