How To Optimize Core Web Vitals With A CMS
IntermediateQuick Answer
TL;DR
Target each metric directly: LCP under 2.5s requires fast TTFB via SSG or CDN plus optimized hero images. INP under 200ms requires minimal JavaScript and aggressive code splitting. CLS under 0.1 requires explicit image dimensions and reserved space for dynamic embeds. Measure with both CrUX field data (real users) and Lighthouse lab data (controlled conditions) — they often tell different stories.
Key Takeaways
- LCP: Serve pages from CDN edge (SSG/ISR), optimize the hero image format and size, use fetchpriority="high" on the LCP element
- INP: Audit and reduce JavaScript bundle size, defer non-critical scripts, avoid long tasks on the main thread
- CLS: Set explicit width and height on all images, reserve space for ads and embeds, use font-display: swap
- Measure with CrUX field data in Google Search Console and PageSpeed Insights, not just Lighthouse lab scores