What would be the effect of a missing viewport meta tag in responsive design?

In responsive web design, the viewport meta tag plays a crucial role in ensuring that a website properly adjusts to various screen sizes, such as those of mobile devices and tablets. When this tag is missing, the browser may use a default viewport width that is typically set to the width of a desktop screen. This results in a lack of scaling and responsiveness, meaning that the elements on the page—such as text, images, and layout—do not resize or reposition themselves based on the actual size of the device's screen.

Consequently, users may experience issues like text being too small to read without zooming in or elements overlapping, which can negatively impact user experience. The absence of the viewport meta tag fundamentally hinders the website's ability to provide a fluid and flexible layout, something that is essential for modern web design, especially given the variety of devices used to access content online.

In contrast, a website that properly implements the viewport meta tag can deliver a tailored experience, adjusting layouts and sizes appropriately to fit the user’s device, enhancing usability and accessibility.