Mobile-First Design

Mobile-first design means you design for the smallest screen first, then enhance the layout upward as the screen gets bigger. For example, you might start with the phone width and work toward the desktop, rather than the reverse.

Starting small forces you to decide what matters most, because there is little room for clutter on a phone. Everything else becomes an enhancement layered on top. It is a natural companion to responsive design, and it pushes teams to prioritize content and core tasks rather than shrinking a desktop layout onto a small screen.