In the second part of this course, we will focus on the Page Router of Next.js 13. The Page Router has been the traditional way of handling routes in previous versions of Next.js and remains compatible in version 13. Although the App Router has introduced new features and improvements, the Page Router remains a solid option, especially for projects that require backward compatibility.

In this chapter, we will explore the Page Router in detail and analyze its key differences with the App Router.

What is the Page Router?

The Page Router is the routing system based on the pages/ folder. In this system, each file within the pages/ folder corresponds to a route. This simple and straightforward approach allows routes to be defined very clearly. For example, a file about.js in the pages/ folder will represent the route /about.

Basic Example of Page Router

Creating routes with the Page Router is extremely intuitive. Here is an example of how to define a basic page using the Page Router:

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This system is simple, making it easy to use and understand.

Key Differences between Page Router and App Router

Although both the Page Router and the App Router handle routing in a Next.js application, there are some important differences between them.

Route Structure

• Page Router: Uses a file-based structure within the pages/ folder. Each file or folder within pages/ represents a route in the application.
• App Router: Introduces a folder-based approach within the app/ folder, where routes are defined using folders and files like page.js.

Data Fetching

• Page Router: In the Page Router, functions like getStaticProps, getServerSideProps, and getInitialProps are used to fetch data during the render process.

• App Router: In the App Router, functions like getServerSideProps are integrated directly into route files, providing a smoother experience for data fetching.

Support for Layouts

• Page Router: The Page Router does not have native support for nested layouts. If you need layouts, you must handle them manually using custom components.

• App Router: The App Router has native support for nested layouts, making it easier to create common design structures across multiple pages.

Flexibility and Modularity

• Page Router: While it is easy to use, the Page Router is less flexible than the App Router in terms of modularity and component reuse.

• App Router: With the App Router, routes and components are organized more modularly, making code reuse and maintenance easier for large projects.

Advantages of the Page Router

Despite the improvements introduced by the App Router, the Page Router still has some advantages that make it useful in certain contexts:

1. Compatibility: If you are working on a project that started in previous versions of Next.js, you may prefer the Page Router to maintain compatibility.

2. Simplicity: The file-based approach is simpler to understand and may be more suitable for small projects or teams that prefer simplicity over advanced flexibility.

3. Documentation and Support: The Page Router has been the traditional way of handling routes in Next.js, so the documentation and community support for this approach are extensive.

Disadvantages of the Page Router

• Less Modularity: Unlike the App Router, the Page Router does not offer native support for layouts or a flexible route structure.
• Less Optimizations: The App Router includes optimizations and performance improvements that are not present in the Page Router.

Conclusion

The Page Router remains a valid option for many projects, especially those seeking to maintain compatibility with previous versions or that do not require the advanced modularity of the App Router. However, if you're starting a new project and need flexibility, the App Router might be a better choice.