How to Create a Custom Popup When Closing a Specific Website

Do you want to create a custom popup when someone tries to close a specific website? This can be useful for a variety of reasons, such as prompting users to save their work or ensuring they are aware of unsaved changes. In this article, we will guide you through the process of implementing this functionality using JavaScript and HTML.

Step 1: Adding JavaScript to Your Website

The first step in creating a custom popup on page closure is to add JavaScript to your website. This can be done directly in the head section of your HTML file or in a separate JavaScript file. Here is the basic code snippet you need:

window.onbeforeunload  function(event {
    // Customize the message for the popup
    const message  "Your custom message here";
    // For modern browsers you can set a custom message
     ();
    // This will show the custom message in most browsers
     return message;
    // Older browsers may still display the custom message
    return message;
};

Note that () is used to indicate that the action ( closing the tab or page) has been canceled.

Step 2: Adding Conditions for Specific Pages

If you want the popup to only appear on a specific page, you can modify the code to check the current URL. Here is an example:

window.onbeforeunload  function(event {
    // Check if the current URL is the specific website
    if (  "") {
        // Customize the message for the popup
        const message  "Your custom message here";
        // For modern browsers you can set a custom message
         ();
        // This will show the custom message in most browsers
         return message;
        // Older browsers may still display the custom message
        return message;
    }
};

This will ensure that the custom popup only appears on the page specified.

Important Notes

Browser Behavior

Most modern browsers have limited the customization of the popup messages for security reasons. They typically show a generic message instead of the one you provide. This is a security measure to prevent malicious scripts from displaying misleading or harmful messages.

However, if you need to achieve a specific message, it’s important to test your implementation in different browsers to understand how the popup behaves. Different browsers may have slight variations in their handling of the onbeforeunload event.

User Experience

Overusing popups can frustrate users. This feature is best suited for situations where unsaved changes might be lost. Always use it judiciously and consider the user experience.

Testing

Make sure to test the code in various browsers to see how the popup behaves. Implementations can vary, and you need to ensure that the popup works as intended across different browsers and environments.

Here is a more detailed example of how to handle user interactions and conditional popups:

window.onbeforeunload  function(event {
    // Check if the current URL is the specific page with unsaved data
    if (("")  hasUnsavedData()) {
        // Customize the message for the popup
        const message  "You have unsaved changes. Are you sure you want to leave this page?";
        // For modern browsers you can set a custom message
         ();
        // This will show the custom message in most browsers
         return message;
        // Older browsers may still display the custom message
        return message;
    }
};

Make sure that the condition hasUnsavedData() is implemented to check whether the user has made changes to the data on the page.

Remember, do not apply this feature to pages that do not require it, as this can be frustrating to users. Use it judiciously and ensure that it adds value to the user experience.

Additional Considerations

If you are referring to the popup that appears when you try to close a tab, this is the onbeforeunload event. The JavaScript snippet provided above can be used to implement this behavior:

window.onbeforeunload  function( {
    // Return a custom message to show the popup
    return "Are you sure you want to leave this page?";
};

If you want to allow closing the tab, you can return null or an empty string:

window.onbeforeunload  function( {
    // Do not show the popup if the user is sure to close the tab
    return "";
};

Consider using this feature to prompt users to save their work or to ensure they are aware of unsaved changes. However, make sure to test the implementation in different browsers to ensure it behaves as expected.

As for customizing the text that appears in the popup, while support for directly including a string in the function has been decreasing, you can still customize the message by returning a string from the onbeforeunload function. Remember to test your custom message in different browsers to ensure cross-compatibility.

Here are a few additional considerations:

Best Practices

Security: Always test your implementation in different browsers to ensure compatibility and security. Avoid showing misleading or harmful messages.

Usability: Use this feature judiciously. Do not overuse popups as they can be frustrating for users. Ensure that the popup adds value to the user experience.

Testing: Test your implementation in various browsers and devices to ensure a consistent user experience.

Conclusion

Creating a custom popup when closing a specific website can be a useful feature to ensure users are aware of unsaved changes or to prompt them to save their work. By following the steps outlined in this article, you can implement this functionality in your website using JavaScript. Remember to test your implementation in different browsers and to consider the user experience before adding this feature.