Performance & SEO

Core Web Vitals Checklist for Template-Based Websites

Optimize your static or template-based website for speed, stability, and interactivity with this complete Core Web Vitals checklist.

Why Core Web Vitals Matter

Core Web Vitals are performance signals introduced by Google to measure real-world user experience. If you’re using a template-based site, improving these metrics is key to faster load times, better user engagement, and higher SEO rankings.

1. Optimize Largest Contentful Paint (LCP)

LCP tracks the loading speed of the largest visible content on your page. Improve it by:

  • Compressing and converting images to WebP
  • Inlining critical CSS and deferring non-critical styles
  • Minimizing render-blocking JavaScript
  • Lazy-loading off-screen elements

Goal: Keep LCP under 2.5 seconds.

2. Improve First Input Delay (FID)

FID measures how quickly your site responds to user input. Reduce delays by:

  • Minimizing JavaScript execution time
  • Using async or defer for script loading
  • Breaking up long tasks into smaller functions
  • Reducing third-party script impact

Goal: Keep FID under 100ms.

3. Reduce Cumulative Layout Shift (CLS)

CLS reflects visual stability. Minimize shifts by:

  • Setting width/height for all images and videos
  • Pre-allocating space for dynamic content like ads
  • Avoiding layout shifts caused by late-loading fonts
  • Using font-display: swap for custom fonts

Goal: Maintain CLS under 0.1.

4. Optimize Static Assets

Template-based sites often include excess CSS/JS. Optimize by:

  • Removing unused code (PurgeCSS, UnCSS)
  • Bundling and minifying all scripts and stylesheets
  • Enabling Brotli or Gzip compression
  • Serving assets through a CDN

5. Implement Caching and Preloading

Use browser caching and preload techniques to deliver assets quickly:

  • Set cache headers for CSS, JS, and images
  • Use <link rel="preload"> for fonts and key resources
  • Enable lazy loading for below-the-fold content
  • Adopt HTTP/2 for parallel loading efficiency

6. Ensure Mobile Responsiveness

Choose templates built with mobile-first principles and:

  • Use responsive layout with media queries
  • Ensure legible text and appropriately sized tap targets
  • Use srcset for responsive images
  • Test regularly using Google’s Mobile-Friendly Test

7. Monitor Core Web Vitals

Track performance over time using these free tools:

  • Google PageSpeed Insights
  • Chrome Lighthouse (DevTools)
  • Web Vitals Chrome Extension
  • Google Search Console (Core Web Vitals Report)