By Shad Super in Questions —

How Does Using a Content Delivery Network (CDN) Affect Core Web Vitals, and What Are the Best Practices for Configuration?

Summary

Using a Content Delivery Network (CDN) can significantly improve Core Web Vitals by reducing server latency, which influences Largest Contentful Paint (LCP), First Input Delay (FID) and Cumulative Layout Shift (CLS). Correct configuration in terms of caching, server location selection, content compression, and HTTP/2 adoption is vital in leveraging these benefits.

The Role of CDN in Core Web Vitals

CDN Impact on Core Web Vitals

A CDN stores copies of your website's content on multiple geographical locations, known as Points of Presence. This strategic placement reduces the distance between a user and the server, lowering the server response time. The reduced latency contributes positively to LCP and FID, vital components of Core Web Vitals [Evaluating Page Experience, Google Developers 2020].

Best Practices for CDN Configuration

Caching

Ensure your CDN is configured to cache as much content as possible to minimize requests to the origin server. Moreover, the Time to Live (TTL) setting should also be maximized to ensure the CDN serves cached content for extended durations [What is CDN Caching, Imperva].

Content Compression

GZip or Brotli compression should be enabled on your CDN which helps in reducing file sizes and speed up content delivery. This contributes to better LCP values [Enable Text Compression, 2021].

Server Location Selection

Choose a CDN provider with a substantial number of server locations or PoPs worldwide to serve content from the nearest servers to your users. This reduction in physical distance contributes to faster asset delivery and improved LCP and FID metrics [Performance - CDN, Cloudflare].

Adopt HTTP/2

HTTP/2 adoption comes with performance benefits like header compression, multiplexing, and server push. These features can speed up webpage delivery and positively affect LCP and FID times [HTTP2 Fundamentals, Google Developers].

Conclusion

When correctly configured, a CDN can deliver substantial benefits to a website's Core Web Vitals. These include reduced server latency, improved load speed, and enhanced user experience. This necessitates a meticulous configuration approach, prioritizing caching, server location selection, content compression, and HTTP/2 adoption.

References