Content Delivery Network (CDN)
Visualize how CDNs reduce latency by serving content from edge locations closer to users, with real-time cache behavior and performance metrics.
CDN Settings
Traffic & Cache
What's happening?
Five global regions generate requests to a central origin server. When CDN is ON, edge servers (cloud icons) intercept static requests. A green line is a cache hit (served from the edge). An orange dashed line is a cache miss (edge fetches from origin and caches the result). A red line is dynamic content — always bypasses cache.
Why it matters?
CDNs reduce latency by bringing content geographically closer to users. A user in Asia fetching from a US origin adds 200–300ms of round-trip time; an edge server in the same region cuts that to ~20ms. CDNs also absorb traffic spikes and reduce origin bandwidth costs. Dynamic content (personalized, real-time) can't be cached and must still reach the origin.
Why this exists
A CDN moves content closer to users by serving it from geographically distributed edge caches. The main value is not just speed. It is removing repeated load from the origin while reducing latency for distant users.
Distance creates latency
Even a well-tuned origin feels slow when it is far away. Edge caching shortens the physical path for repeated content.
Origins should serve the uncommon path
The origin should mainly handle cold misses, personalization, or dynamic work. Repeated static delivery belongs at the edge.
Cacheability determines value
A CDN is strongest for static assets and cacheable responses. Highly personalized traffic limits what the edge can absorb.
Key takeaways
- CDNs reduce latency and protect the origin simultaneously.
- They work best for static assets and predictable cache lifetimes.
- Edge misses still need a healthy origin path.
- Cache headers are part of the system design, not just frontend implementation.