SSG vs SSR in Next.js — what are the differences and which to choose?

If you’re building a web application using Next.js, you may have heard about two popular rendering methods: Server-Side Rendering (SSR) and Static Site Generation (SSG). While both of these approaches have their benefits, they also have some trade-offs that you should consider before choosing one for your project.

In this article, we’ll compare SSG vs SSR in Next.js applications and help you determine which one might be the best fit for your needs. We’ll cover the basics of each approach, their advantages and disadvantages, and some real-world examples of when each one might be a good choice.

What is Server-Side Rendering (SSR)?

Server-Side Rendering (SSR) is a rendering method that involves generating HTML on the server and sending it to the client as a fully-formed page. This means that the client receives a complete HTML document that can be rendered immediately without requiring any additional JavaScript or other client-side processing.

SSR is often used for dynamic web applications that require frequent updates or personalized content. It can also help improve the performance of your application by reducing the amount of JavaScript that needs to be downloaded and executed on the client.

What is Static Site Generation (SSG)?

Static Site Generation (SSG) is a rendering method that involves generating a set of static HTML files at build time based on your application’s data and content. These files can then be served directly to the client without requiring any additional server-side processing.

SSG is often used for content-driven websites or applications that don’t require frequent updates or personalized content. It can also help improve the performance of your application by pre-generating all the HTML files at build time, reducing the need for server-side processing.

SSG vs SSR in Next.js — Advantages and Disadvantages

Both SSR and SSG have their advantages and disadvantages, and the choice between them largely depends on the specific requirements of your web application.

Advantages of SSR:

• Improved performance: SSR can help improve the performance of your application by reducing the amount of JavaScript that needs to be downloaded and executed on the client.
• Personalized content: SSR allows you to generate personalized content for each user based on their session, location, or other factors.
• SEO benefits: SSR can help improve your application’s search engine optimization (SEO) by providing search engines with fully-formed HTML pages.

Disadvantages of SSR:

• Increased server load: SSR requires more server-side processing than SSG, which can lead to increased server load and higher hosting costs.
• Slower initial load times: Because SSR requires server-side processing, the initial load time of your application may be slower than with SSG.
• More complex development: SSR can be more complex to implement than SSG, requiring more server-side code and infrastructure.

Advantages of SSG:

• Faster initial load times: Because SSG generates fully-formed HTML pages at build time, the initial load time of your application can be faster than with SSR.
• Lower server load: SSG requires less server-side processing than SSR, which can lead to lower server load and hosting costs.
• Easier development: SSG can be easier to implement than SSR, requiring less server-side code and infrastructure.

Disadvantages of SSG:

• Limited dynamic content: SSG is best suited for content-driven websites or applications that don’t require frequent updates or personalized content.
• SEO challenges: SSG can present some challenges for SEO, such as managing duplicate content or ensuring that search engines can crawl dynamic content.

Real-World Examples

To help illustrate the differences between SSR and SSG, let’s look at a couple of real-world examples.

Example 1: E-commerce Website

For an e-commerce website with a large catalog of products, SSR may be the better choice. This is because the website likely requires frequent updates and personalized content, such as user-specific pricing, shipping rates, and availability. With SSR, you can generate personalized content on the server and send it directly to the client, without requiring any additional client-side processing.

Additionally, an e-commerce website may also benefit from the SEO advantages of SSR, as fully-formed HTML pages can provide search engines with more information about the website’s products and categories.

Example 2: Blogging Website

A blogging website that publishes new articles on a regular basis may be better suited for SSG. This is because the website’s content is largely static and does not require frequent updates or personalized content. With SSG, you can generate a set of static HTML files at build time and serve them directly to the client, resulting in faster load times and lower server load.

However, managing duplicate content and ensuring that search engines can crawl dynamic content may present some challenges for SEO on a blogging website using SSG.

SSG vs SSR in Next.js — Conclusion

When it comes to choosing between SSR and SSG in Next.js applications, there is no one-size-fits-all answer. The choice largely depends on the specific requirements of your web application and the trade-offs that you are willing to make.

If your application requires frequent updates or personalized content, SSR may be the better choice. However, if your application’s content is largely static and does not require frequent updates, SSG may be the better choice.

By weighing the advantages and disadvantages of each approach and considering some real-world examples, you can make an informed decision about which rendering method is right for your Next.js application.

This article was previously published on Chop-Chop blog.