Mobile-First Indexing Is Complete: Desktop Scores Don't Matter Anymore
On January 1, 2026, Google completed mobile-first indexing. Desktop PageSpeed scores no longer matter for ranking. Only mobile speed counts. Yet 73% of businesses still optimize desktop first. This is costing them rankings.
Optimize desktop first
Mobile-first now
Traffic loss typical
What Changed on January 1, 2026
Google turned off desktop indexing completely. Before January 2026, Google maintained both a mobile index and a desktop index. If your mobile site was slow but desktop was fast, you'd rank based on desktop.
Not anymore. Google now has a single index, and it's 100% mobile-based. Your desktop scores are irrelevant.
How This Impacts Your Rankings
Before (Pre-January 2026)
The Problem: 73% Still Optimize Desktop First
Most development teams work on desktop first, then make mobile responsive. This usually means:
- • Desktop gets 15KB of CSS → Mobile gets same 15KB (wasteful)
- • Desktop renders 1000 DOM nodes → Mobile renders all 1000 (slow)
- • Third-party scripts load on desktop → Same scripts block mobile (catastrophic)
- • Images optimized for desktop → Mobile gets full 1920px images (40x too large)
These sites rank #3-5 on desktop, but #20+ on mobile. Google now only cares about that #20+ ranking.
How to Optimize for Mobile-First Indexing
Reverse your development approach:
1. Optimize Mobile First, Enhance for Desktop
Build for 375px mobile first. Make it fast. Then add enhancements for desktop. Never share heavy CSS/JS that mobile doesn't need.
2. Test on Real Mobile Devices
Test on actual iPhones and Android phones on 3G connection. Don't just use Chrome DevTools.
3. Use Google Search Console Mobile Report
Check "Mobile Usability" and "Core Web Vitals" in Google Search Console. These are the only rankings that matter now.