Definition
A CDN (Content Delivery Network) is a network of servers distributed worldwide that store copies of a website's resources. Resources are served from the server geographically closest to the user, reducing latency and load time. Popular CDNs include Cloudflare, Akamai, Fastly, and AWS CloudFront. In addition to performance, CDNs offer DDoS protection and improve site availability. Using a CDN has a direct positive impact on Core Web Vitals, particularly TTFB and LCP, which are Google ranking factors. For international sites, a CDN is nearly essential as it guarantees fast response times regardless of the user's country. Proper configuration of cache headers on the CDN is essential to maximize benefits.
Key Points
- Reduces latency by serving content from the nearest server
- Provides protection against DDoS attacks
- Major CDNs: Cloudflare, Akamai, Fastly, AWS CloudFront
Practical Examples
International site
A French site visited from Brazil shows 5.2s loading time. With a CDN in South America, it drops to 1.8s.
DDoS protection
During a DDoS attack, the Cloudflare CDN absorbs malicious traffic and keeps the site online.
Frequently Asked Questions
Yes, even locally. A CDN reduces TTFB, protects against DDoS, and improves Core Web Vitals. Cloudflare has a free plan.
Cloudflare (free, performant), Fastly (fast), or AWS CloudFront (AWS integrated). Choice depends on your budget.
Go Further with LemmiLink
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Last updated: 2026-02-07