Key Takeaways:
- Google uses the mobile version of your website as the primary basis for rankings
- Content only visible on desktop may be ignored by Google
- Responsive design is the recommended approach for mobile optimization
More than 60 percent of all Google searches come from mobile devices. Google has responded: Since 2019, Mobile-First indexing is the default for new websites, since 2021 for all.
This means: Google primarily evaluates your mobile website. If content is missing there that exists on desktop, it practically doesn't exist for Google. Ignoring this costs rankings.
What Mobile-First Indexing Means
In the past, Google primarily crawled the desktop version of a website. The mobile version was secondary. This has reversed.
Google's crawler (Googlebot) now visits your website with a mobile user agent. It sees what a smartphone user sees. Based on this, content is indexed and rankings are determined.
For desktop searches, Google still uses the mobile version. Your desktop page can be excellent – if the mobile version is poor, all rankings suffer.
The Three Approaches for Mobile Websites
| Approach | Description | Recommendation |
|---|---|---|
| Responsive Design | One URL, layout adapts | Best choice |
| Dynamic Serving | One URL, different HTML versions | Complicated |
| Separate mobile URL | m.example.com | Outdated |
Responsive Design is the clear winner. A single URL for all devices, the layout automatically adapts to screen size. No duplicate content risk, easy maintenance, recommended by Google.
Separate mobile domains (m.example.com) were common ten years ago. Today they cause unnecessary effort and potential SEO problems. If you still have one, migrating to responsive design makes sense.
Typical Mobile-First Problems
Hidden Content
Many websites hide content on mobile devices to save space. Accordions, tabs, or completely hidden sections are common.
Google treats hidden content differently since the Mobile-First update. Content in tabs or accordions is generally indexed but may be weighted less. Completely hidden content (display: none only on mobile) may be ignored.
The solution: All important content should be accessible on mobile too. Accordions are fine if content appears on interaction.
Different Content on Mobile and Desktop
If your mobile version has less text, fewer images, or fewer internal links than the desktop version, Google only sees the reduced version. This can cost rankings.
Check critically: Is anything important missing on mobile? Navigation links that only appear on desktop? Text sections hidden on small screens?
Touch Targets Too Small
Links and buttons that are too small or too close together frustrate mobile users. Google measures this as part of Core Web Vitals.
The recommendation: Touch targets should be at least 48x48 pixels. The spacing between clickable elements should be at least 8 pixels.
Slow Load Times
Mobile connections are often slower than desktop. If your page takes forever to load on 4G, user experience and rankings suffer.
Load speed is even more critical on mobile. Optimize images, minimize JavaScript, and use lazy loading.
Mobile-First Checklist
Check these points for your website:
- Responsive design active? The page automatically adapts to all screen sizes
- Same content? Mobile and desktop show the same texts, images, and links
- Meta tags present? Title, description, and structured data on the mobile version
- Navigation works? All menu items are accessible on mobile
- Images load? All images display correctly and aren't cropped
- Videos playable? Embedded videos work on smartphones
- Pop-ups not intrusive? No aggressive overlays covering content
Avoiding Intrusive Interstitials
Pop-ups that cover the entire screen on mobile devices can lead to ranking losses. Google calls them "intrusive interstitials."
Allowed:
- Cookie notices (legally required)
- Age verification (if necessary)
- Small banners that take up little space
Problematic:
- Pop-ups that immediately cover all content
- Interstitials that are hard to close
- Multiple pop-ups in succession
Viewport Configuration
The viewport meta tag is a prerequisite for mobile optimization:
<meta name="viewport" content="width=device-width, initial-scale=1">
This tag tells the browser that the page is optimized for mobile devices. Without this tag, your page renders on smartphones like a desktop page – tiny and unreadable.
Check if this tag is in your page's head section. Almost all modern CMS set it automatically, but it doesn't hurt to verify.
Testing Mobile-Friendliness
Google offers several ways to check your mobile optimization:
- Google Search Console: The "Mobile Usability" report shows problems
- PageSpeed Insights: Tests load time and shows mobile-specific issues
- Chrome DevTools: Simulates various mobile devices in the browser
Also test on real devices. Emulators don't show all problems that occur on an actual smartphone.
Check your mobile performance with our Speed Analyzer and get specific optimization tips.
Frequently Asked Questions
Will desktop rankings suffer if the mobile site has problems?
Yes. Since Google primarily indexes the mobile version, mobile problems affect all rankings – including for desktop searches. A poor mobile site hurts the entire website.
Do I need to create an AMP version of my site?
No, AMP is not necessary. Google has confirmed that AMP is not a ranking factor. A well-optimized responsive website is sufficient. AMP can offer benefits in certain cases but isn't required.
How do I know if my website has switched to Mobile-First?
In Google Search Console, you can see the primary crawler under "Settings." If it shows "Googlebot Smartphone," your website has switched to Mobile-First indexing. For most websites, this is already the case.