Delayed Homepage Loads Caused by JavaScript Deferral in Airlift

Summary:

A client’s WordPress homepage appeared to load slowly—even with strong performance scores and solid page speed metrics. Integriti Studio traced the issue to an Airlift plugin setting related to JavaScript deferral and executing JavaScript on user interaction. Here’s how the delay was identified and resolved to restore a smooth, immediate user experience and better Core Web Vitals.

Issue Background:

Although tools like BlogVault, PageSpeed Insights, and GTMetrix are commonly used for web performance testing, BlogVault showed excellent performance stats (94%+) for this WordPress site. However, users noticed a lag before any primary content appeared on the homepage during the initial page load. GTMetrix failed to complete its analysis, and the client became concerned about website speed, first impressions, conversion impact, and bounce rates despite effective caching.

Diagnosis:

• Performance looked fine on paper — fast scores, minimal page size, reduced HTTP request count, optimized cache behavior, and no obvious render-blocking warnings.
• Visual lag persisted — the homepage page content didn’t visibly load until a mouse movement or user interacts with the site, indicating page rendering and JavaScript execution delays.
• Plugin culprit identified — Airlift’s “Execute JavaScript on user interaction” toggle, designed to defer non-essential JavaScript files, was the likely cause of the page load bottleneck affecting the main thread.
• Dashboard mismatch — Even though the setting appeared turned off in the plugin dashboard, it was still affecting behavior, a common issue when multiple plugins or automation-based optimization tools are involved.

Resolution Steps:

Disable Airlift temporarily

Confirmed that turning off the WordPress plugin resolved the rendering delays, isolating the root cause without downtime or breaking your site.

Deep dive into plugin settings

Reviewed Airlift’s plugin settings, caching strategies, and JavaScript execution rules, and found the problematic toggle visually disabled—but still active behind the scenes.

Vendor support collaboration

Contacted BlogVault/Airlift support to report the UI discrepancy, exclusion behavior, and ensure the setting was fully deactivated across all URLs and cache layers.

Final validation

Once the bug was addressed, page content began loading immediately without requiring interaction, restoring proper page rendering, smoother experience, and better user experience across desktop and mobile cache.

Final Outcome:

The homepage now loads instantly, delivering a polished and responsive first impression with improved load times and site loads behavior. The issue—caused by a hidden plugin behavior tied to JavaScript deferral—highlighted the importance of troubleshooting beyond surface-level metrics, always testing real user experience, and validating performance with developer tools, not just scores.

Experiencing invisible delays or inconsistent load behavior on your WordPress site, even with cache plugins, CDN setups, or tools like WP Rocket, LiteSpeed Cache, or Cloudflare?

Integriti Studio can help uncover hidden blockers, optimize JavaScript code, CSS delivery, caching strategies, and ensure faster pages without breaking functionality—improving SEO, conversions, and overall website speed.

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