A mobile-first strategy is a strategy that prioritizes mobile design over desktop design.
But it doesn't just focus on development for mobile phones. It also includes optimizing the usability of websites and reducing unnecessary elements in apps and on websites.
When you design a product for mobile-first, you need to add useful information and design elements to create the desktop product.
This is much easier than deleting elements from the desktop product to create a mobile-friendly website or app.
Design methods like Responsive and Adaptive Web Design often use a top-down method.
This means that the product is first developed for large screens, such as the laptop. Then the elements are adapted for smaller screens, for example, smartphones.
In the process of this development method, the small screens are often overloaded with too much information and elements. This leads, for example, to poor user experience and slow loading times. Furthermore, many internal features provided by the smartphone are often left out.
The Mobile-First strategy, developed by Luke Wrablewski in 2009, avoids this problem. The product is first developed for the smallest display. This ensures that even the smallest device can display the product.
Afterward, the product is developed for larger devices. Here, for example, additional information or other displays can be shown.