Server-side rendering (SSR) can be a useful technique for improving the Search Engine Optimization (SEO) of a React or Next.js application. In this article, we’ll explore how SSR can help to improve SEO and the benefits it offers over client-side rendering.
Introduction to Server-Side Rendering
Server-side rendering (SSR) is a technique used in web development to render the content of a webpage on the server before it is served to the client (usually a web browser). This is in contrast to client-side rendering, where the content is rendered by the client (usually JavaScript) after the page has loaded.
There are several benefits to using server-side rendering, particularly when it comes to Search Engine Optimization (SEO). In this article, we’ll explore how SSR can improve SEO in a React or Next.js application, and the benefits it offers over client-side rendering.
Improved Crawlability
One of the main ways that SSR can improve SEO is by making it easier for search engine bots to crawl and index the content of a website. When a website is server-rendered, the HTML is already fully rendered on the server and served to the bot. This allows the bot to easily understand and index the content of the page.
In contrast, with client-side rendering, the HTML is initially empty and the content is rendered by the client (usually JavaScript) after the page has loaded. This can make it more difficult for search engines to crawl and index the content, as they may not be able to execute the JavaScript and render the content in the same way that a user’s browser does.
Here’s an example of server-side rendering in a Next.js application:
import React from 'react';
import { renderToString } from 'react-dom/server';
import App from './App';
function renderHTML(html) {
return `
<!DOCTYPE html>
<html>
<head>
<title>My App</title>
</head>
<body>
<div id="root">${html}</div>
</body>
</html>
`;
}
export default function serverRenderer() {
return (req, res) => {
const html = renderToString(<App />);
res.send(renderHTML(html));
};
}In this example, we use the renderToString function from React to render the App component to a string of HTML. We then insert this HTML into a template and serve it to the client.
Faster Time-to-Content
Another benefit of SSR is that it can improve the time-to-content for users. When a page is server-rendered, the HTML is already fully rendered and served to the browser, so the user does not have to wait for the client to execute the JavaScript and render the content. This can improve the user experience and also potentially improve the ranking of the website in search results, as search engines may favor websites that provide a faster user experience.
Here’s an example of how to use SSR to improve time-to-content in a React application:
import React from 'react';
import { renderToString } from 'react-dom/server';
import App from './App';
function renderHTML(html) {
return `
<!DOCTYPE html>
<html>
<head>
<title>My App</title>
</head>
<body>
<div id="root">${html}</div>
</body>
</html>`;
}
export default function serverRenderer() {
return (req, res) => {
const html = renderToString(<App />);
res.send(renderHTML(html));
};
}Consistent Content for All Users
Another advantage of SSR is that it ensures that all users see the same content, regardless of their device or whether they have JavaScript enabled. This can be important for SEO, as search engines may penalize websites that serve different content to users based on their device or browser.
For example, if a website serves different content to users on mobile devices than it does to users on desktop devices, search engines may consider this to be manipulative and could potentially penalize the website in search results. By using SSR, you can ensure that all users see the same content, regardless of their device or browser.
Here’s an example of how to use SSR to ensure consistent content for all users in a Next.js application:
import React from 'react';
import { renderToString } from 'react-dom/server';
import App from './App';
function renderHTML(html) {
return `< !DOCTYPE html > <html> <head> <title>My App</title> </head> <body> <div id="root">${html}</div> <script src="/bundle.js"></script> </body> </html>`;
}
export default function serverRenderer() {
return (req, res) => {
const html = renderToString(<App />);
res.send(renderHTML(html));
};
}More Control Over HTML
Finally, SSR gives you more control over the HTML that is served to search engines. With server-side rendering, you can generate the HTML on the server rather than relying on the client to render it. This can make it easier to optimize the HTML for SEO, such as by including relevant keywords and structured data.
For example, you can use server-side rendering to dynamically insert keywords and structured data into the HTML based on the content of the page. This can make it easier for search engines to understand the content of the page and improve its ranking in search results.
Here’s an example of how to use SSR to add keywords and structured data to the HTML in a React application:
import React from 'react';
import { renderToString } from 'react-dom/server';
import App from './App';
function renderHTML(html, keywords, structuredData) {
return `<!DOCTYPE html> <html> <head> <title>My App</title> <meta name="keywords" content="${keywords}"> <script type="application/ld+json">${structuredData}</script> </head> <body> <div id="root">${html}</div> <script src="/bundle.js"></script> </body> </html>`;
}
export default function serverRenderer() {
return (req, res) => {
const keywords = 'some, relevant, keywords';
const structuredData = { "@context": "http://schema.org", "@type": "Organization", "name": "My Company", "url": "https://mycompany.com" } ;
const html = renderToString(<App />);
res.send(renderHTML(html, keywords, structuredData));
};
Conclusion
In conclusion, server-side rendering can offer a number of benefits for SEO in a React or Next.js application. It can improve crawlability, reduce time-to-content, ensure consistent content for all users, and give you more control over the HTML. That said, it’s worth noting that client-side rendering can also be optimized for SEO, and in some cases, it may be more appropriate to use client-side rendering depending on the needs of the application.
By carefully considering the trade-offs between server-side and client-side rendering, you can choose the best approach for your application and ensure that it is optimized for SEO.
