Most people pick a CDN the wrong way. They look at the provider's homepage, see a world map covered in dots, and assume more dots means better coverage. Then they wonder why visitors in Southeast Asia or South America still get slow load times.
The truth is that CDN edge network selection is one of the most impactful decisions you can make for CDN for website speed - and it has almost nothing to do with how many locations a provider advertises.
Why "200+ Edge Locations" Is Often Misleading
CDN marketing is heavy on geography and light on specifics. A provider might list 200 points of presence (PoPs), but half of them could be tiny shared caches with limited bandwidth capacity. A node that serves 50 other customers at peak hours performs very differently than a dedicated, high-throughput facility.
What actually matters when evaluating CDN coverage:
- Tier 1 network peering - Does the CDN connect directly to major ISPs, or does traffic route through middlemen?
- Bandwidth capacity per node - A single large node often outperforms a cluster of underpowered ones.
- Cache hit ratios at regional nodes - Some CDNs collapse traffic to a central origin more often than you'd expect.
- Anycast vs. unicast routing - Anycast routes requests to the nearest healthy node automatically. Unicast does not.
The gap between advertised and real-world performance is where most CDN decisions go wrong.
Start With Your Actual Audience, Not a Map
Before you evaluate a single CDN, pull your analytics data. Where do your real visitors come from? If 70% of your traffic comes from Germany, France, and the UK, a CDN with exceptional North American infrastructure but thin European PoPs will hurt you - not help you.
Run this check before anything else:
- Open Google Analytics or your analytics tool of choice and look at the Users by Country report for the last 90 days.
- Identify your top 5-10 countries by session volume.
- Note any regions with high bounce rates or poor engagement - these often signal slow load times for those users.
Now you have a real target to test against. Any CDN you evaluate should be tested specifically from those locations, not globally averaged.
How to Actually Test CDN Coverage for Your Audience
Use Real User Monitoring (RUM) Data
Synthetic tests from tools like Pingdom or GTmetrix give you a snapshot from one location. They're useful, but they don't tell the full story. Real User Monitoring captures actual load times from actual visitors in actual network conditions.
Tools worth using for RUM:
- Cloudflare Web Analytics - Free, privacy-focused, and shows performance broken down by country.
- SpeedCurve - Deeper RUM with Core Web Vitals segmentation by region.
- Chrome User Experience Report (CrUX) - Google's aggregated field data, accessible through PageSpeed Insights or directly via BigQuery.
If you're already on a CDN and considering switching, run a 30-day RUM baseline first. You want numbers to compare against, not just impressions.
Run Multi-Location Synthetic Tests
For pre-deployment testing, use tools that let you specify test locations:
- WebPageTest - Free, supports dozens of test locations, and shows TTFB, LCP, and waterfall charts per location.
- Catchpoint - More enterprise-grade, but powerful for multi-region performance maps.
- KeyCDN's Performance Test - Quick and free, shows latency from 14 locations globally.
Test the same URL from your five highest-traffic countries. Compare Time to First Byte (TTFB) numbers. A good CDN should bring TTFB under 200ms for cached assets from any of your primary markets. If you're seeing 400-600ms from a region where you have significant traffic, that CDN's edge coverage there is weak.
We covered the TTFB side of this equation in detail in Why Your Time to First Byte Is Costing You Conversions - worth reading alongside your CDN evaluation.
Regional Coverage Gaps to Watch For
Certain regions are consistently underserved by smaller CDN providers. If your audience includes users from any of these areas, pay extra attention during testing:
- Southeast Asia (Indonesia, Vietnam, Philippines) - Many CDNs have thin coverage here despite large internet populations.
- Africa - Coverage is improving, but still patchy for most mid-tier CDNs outside of South Africa and Nigeria.
- South America - Brazil is usually covered. Argentina, Colombia, and smaller markets often aren't.
- Eastern Europe and Central Asia - Nodes in Poland or Romania don't always perform well for traffic in Ukraine, Kazakhstan, or Georgia.
If you have meaningful traffic from these regions and a CDN's PoP map shows nothing there, requests will fall back to the nearest edge node - possibly thousands of kilometres away. That latency shows up as a slow LCP score and a frustrated user.
Understanding CDN Routing: How Requests Actually Find the Nearest Node
Most modern CDNs use Anycast IP routing. When a user requests a resource, their DNS resolver returns the same IP address regardless of location. The network itself routes that request to the closest healthy node based on BGP routing tables.
The practical implication: two CDNs with the same number of PoPs can produce very different latency results depending on their network peering agreements. A CDN that peers directly with a major regional ISP in Brazil will serve Brazilian users faster than one that routes the same request through Miami.
Ask potential CDN providers directly: Which Tier 1 carriers do you peer with in [your target region]? A provider that can't answer this clearly probably doesn't have strong coverage there.
What to Cache - and What Not To
Getting the right edge network is only half the equation. You also need a sensible caching strategy or your CDN won't deliver much speed improvement at all.
Cache these aggressively:
- Images, fonts, and static CSS/JS files (set cache-control headers for 30+ days)
- Full HTML pages for non-logged-in users
- API responses that don't change per user
Do not cache these at the edge:
- Authenticated user pages or shopping cart states
- Dynamic API responses tied to session data
- Admin panels or backend dashboards
A misconfigured CDN that caches session data is a serious security and correctness problem. Set cache-control headers explicitly at the origin. Don't rely on CDN default behaviour to get this right.
For a deeper look at the server-side caching layer that works alongside your CDN, see our overview of server-level caching.
Combining a CDN With Strong Origin Performance
A CDN improves delivery of cached assets enormously. But when a cache misses - when a user requests something that hasn't been cached at the nearest edge node yet - the request falls through to your origin server. If your origin is slow, that cache miss will feel very slow to the user.
This is why CDN for website speed works best as one layer of a broader performance stack, not a standalone fix. Your origin server still needs fast TTFB, good server-side caching (Redis, Memcached, or full-page cache), and low latency to the CDN's backbone.
The relationship between hosting location and baseline latency also matters here. We covered that angle in detail in Why Your Hosting Location Affects Server Response Time More Than Anything Else.
When we configure servers here, we pay close attention to origin response time as its own metric - separate from CDN-cached asset delivery. Both numbers need to be healthy for the full user experience to feel fast.
Checklist: Evaluating a CDN Edge Network
- Pull your analytics and identify your top 5-10 traffic countries before you look at any CDN map.
- Run WebPageTest from each of those countries against a CDN trial or competitor's test URL.
- Check TTFB for cached assets - target under 200ms from your primary markets.
- Ask about Tier 1 peering in your key regions, not just node count.
- Verify the CDN supports Anycast routing, not unicast.
- Review cache-control header behaviour and defaults before going live.
- Set up RUM on your site and monitor regional performance after deployment.
Choosing a CDN based on a map of dots is like choosing a restaurant based on how big the parking lot is. The numbers that matter are the ones measured from where your actual visitors sit - and those are easy enough to get if you know where to look.
