Does Gatsby use server-side rendering?

Server-side rendering (SSR) is an application’s ability to convert HTML files on the server into a fully rendered HTML page for the client . The web browser submits a request for information from the server, which instantly responds by sending a fully rendered page to the client.

Even though Gatsby generates static files, Gatsby apps rehydrate from static HTML rendered by ReactDOM APIs into an app running client-side JavaScript. The general approach as outlined in the React Hydration guide is as follows: Build and render static HTML, creating content and pages with data injected at build time.

js lets you alter the content of static HTML files as they are being Server-Side Rendered (SSR) by Gatsby and Node.

Instead of purely server-side rendering, Gatsby uses the same APIs to create static HTML at build time when you use gatsby build . Gatsby-rendered HTML pages give you the SEO and social sharing advantages of server-side rendering with the speed and security of a static site generator.