Google's Core Web Vitals became a ranking factor in 2021. Four years later, most CMS sites still fail them. This is an opportunity — a fast site in a slow niche stands out both to users and to search engines.
LCP: What actually causes slow Largest Contentful Paint
The LCP element is almost always the hero image or the main heading. The fix depends on which:
If it's an image: Serve WebP at the correct size for each viewport. Use loading="eager" and fetchpriority="high" on the LCP image specifically. Preload it in the <head>. Do not lazy-load it.
If it's text: Ensure your web font is preloaded and uses font-display: swap. A render-blocking font loading event is the single most common cause of slow text LCP.
CLS: The invisible experience destroyer
Cumulative Layout Shift happens when elements move after the page has started rendering. The most common causes on CMS sites:
- Images without explicit
widthandheightattributes - Web fonts that swap and change text dimensions
- Dynamically injected content (cookie banners, chat widgets, ad slots) that push content down
The fix for images is simple: always specify dimensions. For dynamic content, reserve space with CSS before the content loads.
INP: The new metric
Interaction to Next Paint replaced FID in 2024 and is the hardest metric to control on plugin-heavy CMS sites. Every JavaScript event listener is a potential INP bottleneck.
Audit your plugins. Remove anything that adds JavaScript you do not actively use. Defer everything else.
LCP, CLS, INP — these are not just SEO metrics. They directly affect how users experience your site. Here is how I chase green scores on every CMS platform.
- Abdullah Sajid
Leave a comment