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GT VITALS .IN Speed & Web Vitals Optimizer
High Impact • Audit Code: font-display • Savings: 400ms - 1.5s on Mobile

How to Fix "Font Display" & Optimize Core Web Vitals

Resolve the Font Display diagnostic issue flagged by Google Lighthouse to eliminate CPU main thread stalls, reduce page weight, and boost mobile performance scores.

GV By GT Vitals Performance Team
• Lighthouse 13.x & CrUX 2025 • Production Verified
Estimated Fix Time 20 minutes
Expected Lift +12 to +25 points
Google Impact LCP & INP

Technical Breakdown: What Causes This Issue?

The "Font Display" diagnostic indicates that certain page assets or rendering behaviors are degrading the user experience on mobile devices. Optimizing this aspect improves browser parsing speed and delivers smoother visual stability.

How to detect if your page is affected:

  • Lighthouse flags "Font Display" in the Opportunities or Diagnostics section.
  • Waterfall analysis shows resource bottlenecks related to font-display.
  • Field user experience metrics reflect laggy paints or delayed interactivity.

Step-by-Step Resolution Workflows

WordPress & WooCommerce Solution

In WordPress, install LiteSpeed Cache or WP Rocket. Enable CSS/JS minification, asset deferral, and page caching. Audit installed plugins and remove unused extensions.

// Recommended functions.php snippet add_filter('script_loader_tag', function($tag, $handle) { if (is_admin()) return $tag; if (strpos($tag, 'defer') !== false) return $tag; return str_replace(' src=', ' defer src=', $tag); }, 10, 2);

Frequently Asked Questions

Why is Font Display important for SEO?

Google uses PageSpeed and Core Web Vitals as direct ranking signals. Fixing Font Display boosts your Lighthouse score and mobile search visibility.

How long does it take for Google to reflect these changes?

CrUX field data updates over a 28-day rolling window, but Lighthouse and GT Vitals audits reflect your code optimizations immediately.

Will this fix break any existing functionality?

When implemented carefully using script deferral and caching, all interactive features remain intact. Always test checkout and forms after optimizing.

Audit Your Live Website

Test if your domain passes this audit with sub-2s mobile loading:

Speed Sprint Service

Want guaranteed 90+ score without breaking anything?

Our senior performance engineers optimize your assets, configure server-level caching, and fix font-display with a 100% money-back guarantee in 48 hours.

Fix on WhatsApp (₹8,999)
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