| Error: The default export is not a React Component in page in Next.js: Causes and How to Fix

Error: The default export is not a React Component in page in Next.js: Causes and How to Fix

February 10, 2025

Discover common causes and solutions to the Next.js error: "The default export is not a React Component in page." Streamline your debugging process today.

What is Error: The default export is not a React Component in page in Next.js

Error: The Default Export is Not a React Component in a Page

This error arises when a Next.js page does not export a default React component. Next.js pages must export a React component, which will be rendered when the page is navigated to.

Next.js expects every file in the pages directory to export a component by default because these files are mapped to routes.

If the default export is not a valid React component, this error is thrown, indicating a discrepancy in expected behavior.

Code Examples

A typical example of incorrect code that would cause this error is exporting a non-component entity, such as a string or a number:

// pages/index.js

const greeting = "Hello, world!";
export default greeting; // This will cause the error

To resolve the error, ensure the default export is a valid React component:

// pages/index.js

function HomePage() {
  return (
    <div>
      <h1>Hello, world!</h1>
    </div>
  );
}

export default HomePage; // Correct way to export a component

Key Points

The default export in a page should always be a React component.

Ensure the exported entity is a function or class that returns JSX, as these constitute valid React components.

Errors like this one highlight the importance of adhering to expected patterns and conventions in Next.js project structure.

What Causes Error: The default export is not a React Component in page in Next.js

Reasons for "The default export is not a React Component in page" Error in Next.js

Incorrect Default Export: In a Next.js page, the default export should be a React component. If it’s anything else, such as a plain object or a non-component function, this error will occur. Next.js expects the default export to properly render the UI.

File Not Exporting a Component: Sometimes, a file meant to be a page might not export a component at all. This can happen if the export statement is missing or if the component export is mistyped or mismatched.

Anonymous or Inline Functions: Using anonymous functions or inline functions as default exports can sometimes lead to this error; React components need to be defined as proper functional or class components.

Incorrect Import Paths: If a component is imported incorrectly due to a typo in the file path or extension, the export might not behave as expected. This can make it seem like the default export isn’t a React component.

Non-Returning Functional Components: Functional components must return JSX. If a functional component does not return anything, it could cause the exported default to seem like it's not a component.

// An example of a functional component that correctly exports

export default function HomePage() {
  return (
    <div>
      <h1>Welcome to My Page</h1>
    </div>
  );
}

How to Fix Error: The default export is not a React Component in page in Next.js

Verify Default Export

Ensure the default export from your file is a valid React component. A React component should be defined as a function or class that returns JSX.

If you're exporting a utility function, an object, or a non-component value, you'll encounter this error. Double-check the export type.

// Correct: Default export of a React component
function MyComponent() {
  return <div>Hello, Next.js</div>;
}

export default MyComponent;

Check File Extensions

Ensure you're using the correct file extension. Next.js pages should use either .js, .jsx, .ts, or .tsx as file extensions.

If you miss the extension, Next.js might not recognize your file as a component path, causing this error.

Update Folder Structure

Next.js expects your page components to reside within the pages directory. Place your file in the appropriate folder for automatic routing.

If your file is misplaced outside this directory structure, Next.js might not treat it as a valid page component.

Refactor Export Statements

Ensure that your component exporting inline is correctly formatted. If needed, refactor to a separate export statement after the component definition for clarity.

// Inline export
export default function MyPage() {
  return <div>Welcome to My Page</div>;
}

// Separate export
function MyPage() {
  return <div>Welcome to My Page</div>;
}

export default MyPage;

Check NPM/Yarn Dependencies

Ensure your React and Next.js versions are compatible. Sometimes, mismatches in dependency versions can cause unexpected errors.

Update your dependencies by running:

npm update

yarn upgrade

Consult Documentation and Logs

Consult Next.js official documentation if issues persist. They often have examples and troubleshooting steps for similar issues.

Check browser and server console logs for additional errors that may provide more context.

Rebuild the Application

Sometimes clearing the package cache and rebuilding the application resolves any lingering build artifacts or misconfigurations.

Perform clean build operations to ensure all cached data is refreshed:

npm run clean

npm run build

By following these steps, you should be able to fix the error concerning the default export not being a React component within a Next.js environment.