SSR stands for Server-Side Rendering and refers to a technique where the web page's content is generated and rendered on the server before it is sent to the browser. This means that when a user requests a webpage, the HTML is built on the server and sent as a finished page to the browser, in contrast to client-side rendering (CSR), where the browser first downloads an empty HTML page and then fills it with content using JavaScript.
How does SSR work?
When a user visits a webpage that uses SSR, the following happens:
- Request to the server: The user requests a page by entering a URL or clicking a link.
- Server generates HTML: The server gathers data, builds the HTML structure for the page, and sends the finished HTML page back to the user.
- The browser displays the page: The browser receives a finished HTML page and shows it to the user immediately, often faster than if the page had to be generated via JavaScript on the client.
In contrast to client-side rendering (CSR), where the browser must first download JavaScript and execute it to build the content, SSR is faster because the HTML is already ready when it arrives.
Why is SSR important?
SSR is important for several reasons, especially when it comes to performance and search engine optimization (SEO). Here are some benefits:
- Better performance for users: Pages rendered on the server can often load faster for users, especially on slow connections. Since content is sent as finished HTML, the user can see something on the screen almost immediately.
- Improved SEO: Search engines like Google prefer to index pages where the content is already in HTML form. With SSR, the entire page content is delivered as static HTML, which can improve indexing and thus SEO results.
- Better for sharing on social media: When a page is server-side rendered, its metadata (such as titles and descriptions) are also readily accessible, which can improve previews and links shared on social media.
When is SSR used?
SSR is often used in web applications where faster loading times and SEO optimization are important factors. It is typically used in frameworks such as Next.js (for React applications) or Nuxt.js (for Vue.js), where you can get the best of both worlds — fast server-side rendering and dynamic features on the client.
All in all, SSR is a powerful technique for improving the user experience and ensuring better visibility in search engines, especially for JavaScript-heavy applications.