Next.js App Router vs Pages Router: Which One is Better

Next.js, a popular React framework, has revolutionized web development with its powerful routing systems. However, with the introduction of the App Router in Next.js 13, developers now face a choice: Should they stick with the traditional Pages Router or migrate to the newer App Router? Both have their strengths and weaknesses, and the right choice depends on your project’s complexity, performance needs, and development preferences.

In this guide, we’ll break down the key differences, use cases, and trade-offs between the two routers to help you decide which one is better for your project.

What is the Pages Router?

The Pages Router is the original routing system in Next.js. It uses a file-based routing approach, where every file in the pages directory automatically becomes a route. For example:

• pages/index.js → /
• pages/about.js → /about
• pages/blog/[slug].js → /blog/:slug (dynamic route)

This simplicity makes the Pages Router ideal for beginners and projects with straightforward routing needs.

What is the App Router?

The App Router, introduced in Next.js 13, is a more advanced routing system designed for modern web applications. It uses a directory named app and introduces features like:

• React Server Components: Improved performance by rendering components on the server.
• Streaming: Progressive loading of UI components.
• Nested Layouts: Easier management of complex UIs.
• Enhanced Data Fetching: Built-in support for async components.

The App Router is the future of Next.js, and Vercel (the company behind Next.js) recommends it for new projects. However, it comes with a steeper learning curve and some performance trade-offs.

Key Differences Between App Router and Pages Router

Simplicity vs. Control

• Pages Router: Simple and intuitive. It’s perfect for static sites or apps with basic routing needs.
• App Router: Offers more control and flexibility, making it better suited for complex applications with dynamic routing, nested layouts, and advanced data fetching.

Example:

• In the Pages Router, a blog post route might look like pages/blog/[slug].js.
• In the App Router, the same route would be app/blog/[slug]/page.js, with support for nested layouts like app/blog/layout.js.

Convention vs. Configuration

• Pages Router: Relies on file-based conventions. Routes are automatically generated based on the file structure.
• App Router: Uses configuration-based routing, allowing developers to define routes programmatically.

Why It Matters:

• The Pages Router is easier for beginners but can become cumbersome in large projects.
• The App Router provides more flexibility but requires a deeper understanding of Next.js.

Learning Curve

• Pages Router: Beginner-friendly and widely documented. It’s a great starting point for developers new to Next.js.
• App Router: More complex, especially for those unfamiliar with React Server Components or streaming. However, it’s more familiar to developers with experience in other modern frameworks.

File Structure

• Pages Router:
  • Routes are defined by files in the pages directory.
  • Dynamic routes use square brackets (e.g., [slug].js).
• App Router:
  • Routes are defined by folders in the app directory.
  • Each route has a page.js file for the UI and optional files like layout.js or loading.js.

Example:

• Pages Router: pages/about.js → /about
• App Router: app/about/page.js → /about

Features

• Pages Router:
  • Supports Static Site Generation (SSG) and Server-Side Rendering (SSR).
  • Limited support for nested layouts.
• App Router:
  • Introduces React Server Components and streaming.
  • Supports nested layouts, error boundaries, and loading states out of the box.

Performance

• Pages Router:
  • Generally faster for simple applications.
  • Better for SEO and initial load performance due to its simplicity.
• App Router:
  • Can be slower in terms of requests per second due to the overhead of server components and streaming.
  • However, it offers better performance for complex apps with dynamic content.

Performance Trade-Off:

• The App Router’s advanced features come at a cost. For example, server-side rendering and streaming can increase response times compared to the Pages Router.

When to Use the App Router

The App Router is ideal for:

1. Single-Page Applications (SPAs): Its support for nested layouts and dynamic routing makes it perfect for SPAs.
2. Complex Routing Needs: If your app requires advanced routing patterns, the App Router is the way to go.
3. Modern Features: Need React Server Components, streaming, or enhanced data fetching? The App Router has you covered.
4. Future-Proofing: As the recommended approach by Vercel, the App Router is the future of Next.js.

When to Use the Pages Router

The Pages Router is better suited for:

1. Static Sites: If you’re building a simple static website, the Pages Router is easier to set up.
2. Beginners: Its simplicity makes it a great choice for developers new to Next.js.
3. SEO-Centric Projects: The Pages Router’s straightforward structure can lead to better SEO and faster initial load times.
4. Legacy Projects: Migrating to the App Router can be time-consuming, so it’s often better to stick with the Pages Router for existing projects.

Developer Experiences and Opinions

The debate between the two routers is ongoing:

• App Router Fans: Many developers appreciate its flexibility and modern features. They find it easier to manage complex UIs and dynamic content.
• Pages Router Advocates: Some developers prefer the simplicity and stability of the Pages Router, especially for smaller projects.

Common Complaints:

• The App Router can feel unstable or unpredictable, especially in its early versions.
• Performance issues, such as slower response times, have been reported.

The Good News:
The App Router has improved significantly since its release, and Vercel is actively addressing performance and stability concerns.

Migration Considerations

If you’re considering migrating from the Pages Router to the App Router, keep these points in mind:

1. Refactoring Effort: Migrating can require significant changes to your file structure and codebase.
2. Learning Curve: Your team will need to learn new concepts like React Server Components and streaming.
3. Performance Testing: Test thoroughly to ensure the App Router meets your performance requirements.

Final Thoughts: Which One is Better?

The choice between the App Router and Pages Router ultimately depends on your project’s needs:

• Choose the Pages Router if you’re building a simple static site, prioritizing SEO, or just starting with Next.js.
• Choose the App Router if you need advanced features, complex routing, or want to future-proof your project.

Both routers have their place in the Next.js ecosystem, and you can even use them side-by-side in the same project. For example, you might use the Pages Router for static pages and the App Router for dynamic sections of your app.

Conclusion

The Next.js App Router and Pages Router represent two different approaches to routing, each with its own strengths and weaknesses. While the Pages Router is simpler and more performant for basic use cases, the App Router offers unparalleled flexibility and modern features for complex applications.

As Next.js continues to evolve, the App Router is likely to become the standard. However, the Pages Router remains a reliable choice for simpler projects. By understanding the differences and trade-offs, you can make an informed decision that aligns with your project’s goals and your team’s expertise.

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