What Is Mobile-First Indexing?
Mobile-first indexing means Google treats the mobile version of your website as the primary version. When Google crawls and evaluates your page, it looks at the mobile display — not the desktop version. This applies to both indexing and rankings.
Google gradually introduced mobile-first indexing starting in March 2018. In October 2023, Google declared the transition substantially complete, and since July 2024, all websites without exception are indexed using the smartphone crawler.
The reason is simple: Over 60% of global web traffic comes from mobile devices. In many industries, the share is even higher. Google decided to prioritize the display that the majority of users see.
Google exclusively evaluates the mobile version of your website. If content is only visible on desktop, it doesn't exist for Google.
What This Means for Your Website
Same Content on Mobile and Desktop
All content visible on the desktop version must also be present on the mobile version. If you hide text, images, or entire sections on mobile (e.g., with display: none in a media query), Google doesn't see this content and won't consider it for rankings.
Responsive Design Is Mandatory
Responsive design means your website's layout automatically adapts to the screen size. This is Google's recommended approach. The alternative — separate mobile URLs (m.example.com) — is technically more complex and error-prone.
Touch-Friendliness
Buttons and links must be large enough to tap with a finger. Google recommends a minimum size of 48x48 pixels for clickable elements and a minimum spacing of 8 pixels between interactive elements.
Readable Font Sizes
Text must be readable without zooming. Google recommends a base font size of at least 16 pixels. Smaller text forces users to zoom — a negative signal for user experience.
How to Test Your Page on Mobile
Chrome DevTools: Press F12, click the smartphone icon (Toggle Device Toolbar), and select a device. This shows your page as it appears on various smartphones.
PageSpeed Insights: Gives you separate scores for mobile and desktop. The mobile score is more important — and often significantly worse than the desktop score.
Google Search Console: Under "Mobile Usability," Google shows which of your pages have problems on mobile devices.
Static HTML: The Mobile Advantage
Static HTML websites like proofofreach.de have a natural advantage in mobile performance. No JavaScript framework loading slowly on smartphones. No WordPress with dozens of plugins. No server-side rendering increasing Time-to-First-Byte.
With clean, responsive CSS and optimized images, static HTML pages easily achieve mobile performance scores of 95+. That's a competitive advantage most WordPress websites don't have.
Sources
- Google (Oct 2023): Announcement that Mobile-First Indexing is essentially complete. developers.google.com
- Google (July 2024): Complete migration of all websites to the smartphone crawler. developers.google.com
FAQ
Mobile-first indexing means Google uses the mobile version of your website as the primary version for indexing and ranking. The transition began in 2018 and was fully completed for all websites in July 2024.
Use Chrome DevTools (F12 → smartphone icon), Google PageSpeed Insights with the Mobile tab, or the "Mobile Usability" report in Google Search Console.
Yes. Since Google uses the mobile version as the primary version, mobile performance also influences your rankings for desktop searches.
Last updated: March 25, 2026