How do I defer JavaScript in WordPress?

Use the `script_loader_tag` filter hook in functions.php, skipping jQuery and admin. Code above.

What scripts should not be deferred in WordPress?

jQuery core, analytics (use async), above-fold interactives, document.write users.

Does deferring JS improve WordPress Core Web Vitals?

Yes—LCP drops 0.5-2s, TBT under 200ms. Test with PageSpeed Insights.

Deferring JS in WordPress: The Quiet Fix That Slashes Load Times Without Breaking Sites

Your WordPress site's crawling because of render-blocking JavaScript. Defer it right, and watch pages snap into focus faster—real users stick around longer, bounce rates plummet.

theAIcatchup Apr 08, 2026 3 min read

WordPress code editor with defer JS filter active, PageSpeed score jumping from yellow to green

⚡ Key Takeaways

Defer JS via WP 6.3's script_loader_tag filter for safe, order-preserving loads. 𝕏
Skip jQuery core and analytics—test console and mobile rigorously post-tweak. 𝕏
Pairs with critical CSS for massive Core Web Vitals wins; exposes plugin bloat. 𝕏

Published by

theAIcatchup

Community-driven. Code-first.

#Core Web Vitals #PageSpeed Insights #WordPress performance #defer JavaScript #render-blocking JS

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Originally reported by Dev.to

⚡ Key Takeaways

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