How to Improve Core Web Vitals on Your Website

· Category: Web Performance

Short answer

Improving Core Web Vitals requires optimizing server response times, resource loading, and JavaScript execution. Each metric has specific levers for improvement.

Steps

  1. Improve LCP by optimizing images, using a CDN, and reducing server response time.
  2. Reduce CLS by adding width and height attributes to images and reserving space for ads.
  3. Lower INP by breaking up long tasks, deferring non-critical JavaScript, and using web workers.
  4. Enable text compression with Brotli or Gzip.
  5. Preload critical resources like hero images and above-the-fold CSS.

Tips

  • Use the fetchpriority attribute to prioritize the LCP image.
  • Avoid injecting content above existing content after initial render.
  • Profile JavaScript with Chrome DevTools to find long tasks.

Common issues

  • Third-party scripts often dominate main thread blocking.
  • Responsive images without explicit dimensions still cause layout shifts.