Layouts vs. Templates in Next.js 14: A Guide to Structuring Your App

As a developer working with Next.js, I’m always eager to explore and implement the latest features. Next.js 14 introduces some powerful tools for structuring applications: Layouts and Templates. At first glance, these concepts might seem similar, but they have distinct purposes and behaviors that can significantly impact how you organize your project.

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In this post, I’ll walk you through the differences between Layouts and Templates in Next.js 14. By the end, you’ll have a solid understanding of when to use each and how they can work together to build a well-structured application.

What Are Layouts in Next.js?

In Next.js 14, Layouts serve as the backbone for shared UI components across different pages or routes. Think of them as the scaffolding of your application—wrapping your pages with consistent elements like headers, footers, and navigation bars.

Key Characteristics of Layouts

1. Persistence Across Route Changes

One of the standout features of Layouts is their persistence. When navigating between pages that share the same Layout, the Layout does not unmount. This behavior is crucial for maintaining the state of components within the Layout, like a navigation menu or a sidebar, as you move from one page to another.

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For example, if you have a sidebar that tracks the user’s interaction or state, it will remain intact across page transitions, providing a smoother and more seamless user experience.

2. Nesting Layouts for Complex UI

Layouts are not just a flat layer over your pages—they can be nested. This nesting capability allows you to create complex UI hierarchies. Imagine a global Layout that wraps your entire app with a header and footer, and a nested Layout that adds a sidebar specifically for a dashboard section.

Here’s a quick example:

TypeScript

// app/layout.tsx
export default function RootLayout({ children }) {
  return (
    <html lang="en">
      <body>
        <Header />
        {children}
        <Footer />
      </body>
    </html>
  );
}

// app/dashboard/layout.tsx
export default function DashboardLayout({ children }) {
  return (
    <div className="dashboard-layout">
      <Sidebar />
      <main>{children}</main>
    </div>
  );
}

In this scenario, the DashboardLayout is nested within the RootLayout, providing additional UI elements like the sidebar only when users navigate to the dashboard section.

Exploring Templates in Next.js

While Layouts are great for consistency across pages, Templates provide more flexibility in defining the structure of individual pages that share similar designs but may need different content or layout arrangements.

Key Characteristics of Templates

1. Re-rendering on Route Changes

Unlike Layouts, Templates do not persist across route changes. This means that when navigating from one page to another that shares the same Template, the entire Template re-renders. This behavior is particularly useful when the content between pages is dynamic and you don’t need to maintain state between navigations.

For instance, in a blog application where different posts use the same Template, you would want the Template to re-render entirely when moving from one post to another, ensuring that the content and any page-specific logic are freshly loaded.

2. Structuring Content with Flexibility

Templates allow you to define a shared structure for multiple pages, but with more control over the individual content areas. While Layouts focus on wrapping pages with consistent elements, Templates provide the structure within the page itself, making it easier to control different sections and their content.

Here’s how you might define a Template for blog posts:

TypeScript

// app/posts/[id]/template.tsx
export default function PostTemplate({ children }) {
  return (
    <article>
      <header>
        <h1>Blog Title</h1>
      </header>
      <section>{children}</section>
      <footer>
        <AuthorInfo />
      </footer>
    </article>
  );
}

In this example, the PostTemplate structures the blog post with a header, content section, and footer. Each blog post will follow this structure, but the content within the section will differ, making the Template reusable yet adaptable.

Layouts vs. Templates: When to Use Which?

Now that we’ve covered the basics, let’s talk about when to use Layouts and when to use Templates. Understanding their differences is key to making informed decisions on how to structure your Next.js 14 applications.

Use Layouts When:

You Need Consistency Across Pages: If you have UI components like headers, footers, or sidebars that should be present and persistent across multiple pages, Layouts are your go-to solution.
You Want to Maintain State: Since Layouts persist across route changes, they’re ideal when you need to maintain the state of certain components, like a user’s progress in a sidebar or a shopping cart summary.
You Need Nesting for Complex UIs: If your application has different sections that require their own Layouts (like a marketing site with a nested dashboard), the nesting capability of Layouts will allow you to organize these sections cleanly.

Use Templates When:

You Require Flexible Page Structures: Templates are perfect for scenarios where pages share a similar structure but need to load different content or layouts entirely when the route changes.
You Don’t Need State Persistence: If the content between pages is highly dynamic and doesn’t require maintaining state between navigations, Templates will work better as they re-render on every route change.
You’re Structuring Content Rather Than Wrapping It: Templates are more focused on the internal structure of a page rather than wrapping the page with consistent UI elements. This makes them ideal for defining the layout of dynamic content sections.

Conclusion

In Next.js 14, Layouts and Templates offer powerful tools for structuring your applications, each with its distinct use cases. Layouts are persistent, can be nested, and are perfect for maintaining consistency across your application. Templates, on the other hand, offer flexibility and control over the structure of individual pages, with the added benefit of re-rendering on route changes.

By understanding the differences between Layouts and Templates, you can make more informed decisions when organizing your Next.js projects. This will not only improve the maintainability of your code but also enhance the user experience by ensuring your application is both performant and well-structured.