How to Fix the “ReferenceError: Window is not defined” Error

If you are encountering the “ReferenceError: Window is not defined” error in a Node.js or Next.js environment, don’t worry! There are ways to resolve this issue.

First, it’s important to understand that the window object is specific to the browser environment and is not available in server-side JavaScript environments like Node.js.

To learn more about the window object, you can refer to my comprehensive guide on the DOM (Document Object Model).

However, in Node.js, there is no direct workaround for this problem. You will need to locate the specific part of your code where the window object is being accessed and understand why.

It is likely that you are running frontend code in a backend environment, which is causing the error.

In the case of Next.js, you can fix this issue by wrapping the code that needs access to the window object in a conditional statement.

This ensures that the code is executed only when the window object is available, which is typically the case when running in a browser environment.

Here’s an example of how to implement this conditional statement in your Next.js code:

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if (typeof window !== 'undefined') {
  // Your code that requires the `window` object here
}

By using this conditional check, you can limit the execution of the code to only the browser environment, thus fixing the “ReferenceError: Window is not defined” error.

Tags: JavaScript, Node.js, Next.js, Window object