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CDN and Caching

Cloudflare's CDN (Content Delivery Network) is one of the largest in the world, spanning 330+ cities globally. It stores copies of your website's static content at edge locations closest to your visitors, dramatically reducing latency and offloading traffic from your origin server.

Why This Matters

A CDN can reduce your page load time by 50–80% for static assets. Cloudflare's CDN is free and active by default on every proxied domain.

How Cloudflare CDN Works​

flowchart TD
    subgraph Visitors["Global Visitors"]
        US["🇺🇸 US Visitor"]
        EU["🇪🇺 EU Visitor"]
        AS["🇯🇵 Asia Visitor"]
    end

    subgraph Edge["Cloudflare Edge Network (330+ PoPs)"]
        US_POP["US PoP\n(Cached Content)"]
        EU_POP["EU PoP\n(Cached Content)"]
        AS_POP["Asia PoP\n(Cached Content)"]
    end

    ORIGIN["Your Origin Server\n(Single Location)"]

    US --> US_POP
    EU --> EU_POP
    AS --> AS_POP
    US_POP -->|Cache Miss| ORIGIN
    EU_POP -->|Cache Miss| ORIGIN
    AS_POP -->|Cache Miss| ORIGIN

    style ORIGIN fill:#6b7280,color:#fff,stroke:#4b5563
    style US_POP fill:#f6821f,color:#fff,stroke:#e5711e
    style EU_POP fill:#f6821f,color:#fff,stroke:#e5711e
    style AS_POP fill:#f6821f,color:#fff,stroke:#e5711e

What You Will Learn​

LessonWhat It Covers
CDN and Cache FundamentalsHow the CDN works, what gets cached, Cache-Control headers, and cache purging
Speed BrainPrefetch acceleration for faster page navigation
Cache RulesModern, granular caching policies — per path, cookie, header, or country (10 free)
Page Rules (Legacy)The older per-URL rule system, common patterns, and full migration guide
Tiered CacheHierarchical caching that shields your origin and increases cache HIT ratios globally
Cache ReservePersistent R2-backed cache layer that eliminates evictions for long-tail content (paid)
Cache ConfigurationZone-wide settings: Caching Level, Browser Cache TTL, Purge, Dev Mode, Always Online, and more

Prerequisites​

  • Domain added to Cloudflare with proxied DNS records (Module 1)
  • Basic understanding of HTTP headers