What is Mobile-first?
The short answer
Mobile-first is designing and building for the smallest screen first, then adding layout for larger screens, so the core experience works on phones.
Mobile-first, explained
Starting small forces priorities: whatever fits on a phone is what actually matters. Search engines also index the mobile version of pages first.
Questions people ask about Mobile-first
What is Mobile-first?
Mobile-first is designing and building for the smallest screen first, then adding layout for larger screens, so the core experience works on phones.
Related terms
Responsive design is building one website whose layout adapts to every screen size, from phones to wide monitors, instead of separate mobile and desktop sites.
Media queryA media query is a CSS rule that applies styles only when conditions are met, such as a screen width, dark mode preference or reduced-motion setting.
UXUX, or user experience, is how it feels to use a website: whether people can find what they came for, understand it and finish what they started without friction.
UIUI, or user interface, is the visible, clickable surface of a website: buttons, type, colour, spacing, icons and the states each element shows.
Part of the Web Encyclopedia by Apex Flow Digital. Definitions are general knowledge, kept current, with no invented statistics.