Server-side rendering generates the initial HTML for a page on the web server before it is sent to the browser. This means the user receives a fully‑formed page that can be displayed immediately, rather than waiting for JavaScript to build the content in the client. It is commonly used with frameworks such as React to improve the first view experience.
Also called: SSR
Why it matters
Clients see a faster‑loading page, which reduces bounce rates and keeps visitors engaged, leading to higher conversion potential. Search engines can index the content more reliably, helping the site rank better in organic results.
How it works
When a request arrives, the server runs the JavaScript application using a runtime like Node.js and calls a function such as ReactDOMServer.renderToString to produce HTML markup. The server then sends this markup along with a minimal script that will later hydrate the page, allowing the client‑side code to take over for interactivity.
The mistake people make
Many assume that server‑side rendering removes the need for any client‑side JavaScript, but the page still requires hydration to become interactive; skipping this step leaves the site static and broken. Others forget to set appropriate cache headers, causing stale content to be served to users and search engines.
Related terms
hydration, client-side rendering, static site generation, caching
