0Pricing
Next.js 15 Fullstack (App Router + Server Actions) · Lesson

Layouts and Page Components

Master creating nested layouts and page components within the App Router structure for organized UI.

Layouts and Page Components is a free Next.js 15 Fullstack (App Router + Server Actions) lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Next.js 15 Fullstack (App Router + Server Actions) learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

App Router UI Structure

The Next.js App Router organizes your application's user interface (UI) using special files: layout.js and page.js.

This structured approach helps you build consistent UIs that are easy to manage and scale across your mobile app.

What is a Layout?

A layout defines shared UI for a segment of routes. Think of it as a wrapper that surrounds your pages and other layouts.

  • Layouts can contain common elements like navigation bars, footers, or sidebars.
  • They don't re-render when navigating between pages within the same layout, improving performance.

The Root Layout File

Every App Router project must have a root layout file named app/layout.js at the top level of your app directory.

This layout defines the essential HTML structure, including the <html> and <body> tags, for your entire application.

Basic Root Layout Code

The children prop in a layout component is crucial. It represents the content of the nested layouts or pages below it.

This example shows a basic root layout with a header and footer.

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

What is a Page Component?

A page component is defined by a page.js file. This file contains the unique UI content specifically for a given route segment.

  • Each URL path (e.g., /, /about) typically has its own page.js.
  • It renders within its parent layout(s), filling the {children} slot.

Basic Page Component Code

This app/page.js file creates the UI for your root URL (/). It will be automatically wrapped by your app/layout.js.

app/page.js
export default function HomePage() {
  return (
    <main>
      <h1>Welcome to CoddyKit!</h1>
      <p>Start learning Next.js 15 today!</p>
    </main>
  );
}

Creating Nested Layouts

You can create nested layouts by simply adding a layout.js file inside any subfolder within your app directory.

This allows you to apply shared UI to specific sections of your app, like a dashboard or user profile, while inheriting the root layout's structure.

Nested Layout Example

Here's how you'd create a nested layout for a /dashboard route. This dashboard layout wraps all pages within the /dashboard segment.

app/dashboard/layout.js
export default function DashboardLayout({ children }) {
  return (
    <section>
      <nav>
        <p>Dashboard Navigation</p>
      </nav>
      {children} {/* This will be app/dashboard/page.js */}
    </section>
  );
}

app/dashboard/page.js
export default function DashboardPage() {
  return (
    <h1>Dashboard Overview</h1>
  );
}

Layouts & Pages Hierarchy

The rendering order for your UI components flows from the outermost layout to the innermost page:

  • app/layout.js (Root Layout)
  • app/dashboard/layout.js (Nested Layout, if applicable)
  • app/dashboard/page.js (Specific Page Content)

Each layout receives the next level of UI as its children prop.

Quick Check

Test your knowledge on how Next.js App Router structures UI.

Recap: Layouts & Pages

You've learned how Next.js App Router uses layout.js files for shared UI and page.js files for unique content specific to a route.

Understanding this fundamental structure is key to building organized and scalable Next.js applications!

Frequently asked questions

Is the “Layouts and Page Components” lesson free?

Yes — the full text of “Layouts and Page Components” is free to read here on the web, and the Next.js 15 Fullstack (App Router + Server Actions) course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Next.js 15 Fullstack (App Router + Server Actions) course, upgrade to CoddyKit PRO.

What will I learn in “Layouts and Page Components”?

Master creating nested layouts and page components within the App Router structure for organized UI. You practise Next.js 15 Fullstack (App Router + Server Actions) with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start Next.js 15 Fullstack (App Router + Server Actions)?

No prior experience is required. Next.js 15 Fullstack (App Router + Server Actions) on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “Layouts and Page Components” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this Next.js 15 Fullstack (App Router + Server Actions) lesson?

Yes. Every Next.js 15 Fullstack (App Router + Server Actions) lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

All lessons in this course

  1. Layouts and Page Components
  2. Dynamic Routes & Params
  3. Loading & Error UI
  4. Route Groups and Nested Layouts
← Back to Next.js 15 Fullstack (App Router + Server Actions)