Passing Core Web Vitals: A Mobile Page Speed & Ad Optimization Strategy
Client: A large digital news & media publisher with 2M+ monthly visitors.
Challenges We Faced
The client’s mobile traffic was in a nosedive, and they were losing their top rankings due to a poor mobile optimized design:
Failing All Core Web Vitals
The GSC (CWV Report) showed 100% of their URLs were “Failing” on mobile.
High CLS (Cumulative Layout Shift)
Their display ads would “pop in” and shift the text while people were reading, creating a terrible user experience.
Slow LCP (Largest Contentful Paint)
Large, unoptimized hero images were causing a 7+ second mobile load time.
Losing Rankings
Google Search Console showed a 40% drop in mobile impressions YOY as Google’s Mobile-First Indexing penalized them.
Too Many Mobile Ads
Excessive ads slowed page load and annoyed users, reducing engagement and harming mobile SEO performance.
Pass Your Core Web Vitals
“Is your slow, ‘shifty’ mobile site killing your rankings? Our mobile responsiveness optimization will pass Core Web Vitals and boost your traffic.”
Our Approach – How We Solved These Challenges
Mobile Page Speed Optimization
This was our 100% focus. Our mobile responsiveness services team worked with their developers to:
Fix LCP: Implement lazy loading and compress all images.
Fix INP: Defer all non-essential JavaScript (like 3rd-party ad trackers).
Fluid Grid & Media Query Implementation
We fixed the critical CLS issue by adding width and height attributes to all ad slots in the CSS, “reserving the space” so they wouldn’t shift the content.
Image & Media Optimization
We converted all images to the fast-loading WebP format.
Technical SEO (Mobile)
We used Screaming Frog (Mobile User-Agent) to crawl the site as a mobile phone, finding and fixing mobile-only redirect errors.
Results
| Metric | Before | After | Growth |
|---|---|---|---|
| Google PageSpeed Score (Mobile) | 22 | 89 | +304% |
| Core Web Vitals (Mobile URLs) | “Failing” (100% URLs) | “Good” (92% URLs) | Passed |
| Mobile Organic Traffic | 1.2M/mo (Declining) | 1.8M/mo (Growing) | +50% |
Free Core Web Vitals Analysis
“Failing your CWV test? Request a Free PageSpeed Analysis and let our mobile optimized design experts build your optimization plan!”
Advice for Marketers & Brand Owners
- Core Web Vitals are not optional. For publishers, they are a direct and powerful ranking factor.
- CLS (Cumulative Layout Shift) is the silent killer. If your ads are shifting your content, you are actively being penalized by Google.
- Reserve space for your ads. A mobile website design optimization company will always define width and height for ads.
- Check your GSC “Mobile Usability” report. Google is telling you exactly which pages to fix.
Extra Factors That Made It Work
- The fix for CLS by reserving ad space was the single biggest win.
- Deferring the 5 heaviest, non-critical JavaScript files had a massive impact on LCP.
- Using the Google Search Console (CWV Report) to validate our fixes and see Google “pass” the site’s URLs.
