A Content Delivery Network (CDN) stores copies of your content on servers around the world. When users request content, it's served from the nearest location, reducing latency.
How CDNs work
- Your origin server hosts the original content
- CDN edge servers are deployed globally
- Content is cached on edge servers
- Users receive content from the nearest edge location
CDN benefits
- Faster load times: Content served from nearby servers
- Reduced server load: Origin handles fewer requests
- Better availability: Content survives if origin goes down
- DDoS protection: Traffic distributed across network
- Lower bandwidth costs: Caching reduces origin bandwidth
What to serve via CDN
- Static assets (images, CSS, JavaScript)
- Video and audio files
- Software downloads
- Entire websites (static sites)
CDN and Core Web Vitals
CDNs directly impact:
- TTFB: Faster initial response from edge servers
- LCP: Faster delivery of hero images
- FCP: Quicker delivery of initial resources
How VitalSentinel handles this
A CDN's whole job is reducing TTFB across regions, but a misconfigured edge can quietly hurt users in one geography while looking fine elsewhere. VitalSentinel's RUM monitoring segments TTFB and LCP by country and city using real visitor data, so you can spot when your CDN is failing in Sydney but fine in Frankfurt. Your website's revenue insurance against silent regional regressions.
Related Terms
Caching
The process of storing copies of data in a temporary storage location so that future requests can be served faster.
Latency
The time delay between a user action and the system's response, often referring to network delay in web performance.
Server Response Time
The time it takes for a server to respond to a request from a browser, measured from request initiation to receiving the first byte of response.
Time to First Byte (TTFB)
A performance metric that measures the time between the request for a resource and when the first byte of a response begins to arrive.