2026 Edition

Mobile-First Design Checklist

A comprehensive 78-point checklist for implementing mobile-first responsive design on WordPress and custom websites

Last Updated: January 2026
Estimated Audit: 2-3 hours
Mobile-First Design

Download Complete Checklist

Get the PDF version with detailed implementation guides, code snippets, and performance benchmarks.

Your Progress

15%
12 of 78 completed Score: 245/780
3
Critical
8
High Priority
2.5
Hours Left

Foundation & Core Principles

Essential mobile-first baseline requirements

2/10
Mobile-First Viewport Meta Tag i
<meta name="viewport" content="width=device-width, initial-scale=1.0">
Critical 5 min Score: 15
Responsive Breakpoint Strategy
Content-based breakpoints (not device-based) using container queries where possible
Critical 15 min Score: 20
Fluid Typography System
Implement clamp() for fluid type scaling: font-size: clamp(min, preferred, max)
High 30 min Score: 15
CSS Container Queries Implementation
Component-level responsiveness using @container instead of @media where applicable
High 20 min Score: 15
Performance Budget Definition
Set and enforce: Mobile < 1.5MB, LCP < 1.2s, CLS < 0.1
Medium 45 min Score: 10

Performance Optimization

Mobile speed and loading optimizations

0/12
Modern Image Format Delivery
AVIF/WebP with JPEG fallback, responsive srcset, lazy loading
Critical 30 min Score: 20
Critical CSS Extraction
Above-the-fold CSS inlined, remaining styles deferred
High 25 min Score: 15
JavaScript Optimization
Code splitting, dynamic imports, defer non-critical scripts
High 20 min Score: 15
Font Loading Strategy
font-display: swap, subsetting, local() fallback, preconnect to CDN
Medium 15 min Score: 10

Touch & Interaction Design

Mobile-specific interaction patterns

1/8
Touch Target Sizing
Minimum 44×44px interactive elements, 8px spacing between
Critical 10 min Score: 15
Thumb-Friendly Navigation
Primary actions within natural thumb zone (50%-90% of screen height)
High 25 min Score: 15
Touch Gesture Support
Swipe, pinch, tap, and long-press gestures with visual feedback
Medium 20 min Score: 10

Accessibility & UX

Inclusive design and user experience

0/10

Technical Implementation

Code-level optimizations and patterns

0/15

Testing & Validation

Quality assurance and performance testing

0/12

Advanced Features (2026)

Next-generation mobile experiences

0/11

Mobile-First Readiness Score

245

Out of 780 possible points

Beginner
0-260 pts
Intermediate
261-520 pts
Advanced
521-780 pts

Additional Resources

Google Web.dev: Responsive Web Design Basics MDN: CSS Container Queries Documentation PageSpeed Insights Tool Book Free Mobile-First Website Audit