Mobile-first design
A design and development principle that starts with the smallest screen and scales upwards. Directly linked to Google's mobile-first indexing policy — a business-critical architecture decision, not just a UX preference.
MFD
A design and development principle that starts with the smallest screen and scales upwards. Directly linked to Google's mobile-first indexing policy — a business-critical architecture decision, not just a UX preference.
Derivatives & related terms
- Responsive design
- Adaptive design
- Mobile-first indexing
- Breakpoint
- viewport meta tag
- Touch target size
- Progressive Enhancement
- Graceful Degradation
- CSS Grid/flexbox
- Container Queries
- Fluid Typography
SEO tip
Google completed mobile-first indexing for all websites in 2023. Missing content or errors on mobile devices influence organic rankings regardless of desktop performance — mobile is now the primary crawling interface.
Source: Georgia Business & Technology Glossary by Del-Ops Technology & Consulting Team. Last Updated: February 2026.