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CDN industry insights, technical deep-dives and benchmark reports
How to Evaluate CDN Rankings: Core Capabilities Compared and Selection Guide for the Top 10 Global CDN Providers
A CDN ranking is not just about who comes in first. Drawing on CDNChart's current global rankings, this article compares the top ten CDN providers across latency, availability, sample size, network positioning, security capabilities, and use cases, and explains how to move from an initial shortlist based on the rankings to real-world performance testing and POC validation for your own workloads.
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Which Website Speed Test Tool Is Best? 10 Well-Known Website Speed Test Platforms Compared
Website speed testing tools should be chosen based on test regions, carriers, real user data, Core Web Vitals, and waterfall chart capabilities. This article compares 10 platforms, including CDNChart, PageSpeed Insights, GTmetrix, and WebPageTest, and explains how to combine them for different business scenarios.
Which CDN detection tool is best? What information should be returned after entering a domain
A CDN detection tool shouldn't stop at displaying a vendor name. This article explains what a lookup should actually return once you enter a domain—the CNAME chain, response IPs, ASN, HTTP response headers, TLS certificate, detection evidence, and confidence level—and covers command-line cross-verification methods to help you tell apart single-CDN, multi-CDN, and unidentified results.
HTTP or HTTPS for CDN Origin Fetches? Choosing Certificates, SNI, and Ports
Should CDN origin fetches use HTTP or HTTPS? This article explains the difference between edge certificates and origin certificates, how the origin protocol, certificate domain, SNI, Host, and port relate in configuration, and provides curl and OpenSSL commands to troubleshoot 502 errors, certificate mismatches, and origin fetch failures.
Baidu and Google crawling issues after CDN integration: How do I check status codes and blocking rules?
After a site is put behind a CDN, are Baidu and Google failing to crawl it, seeing lower index coverage, or receiving 403, 429, or 5xx responses? This article explains how to check the status codes search engines see, WAF and rate limiting rules, robots.txt, and JavaScript verification pages, and how to properly verify Googlebot and Baiduspider.
Frontend API Requests Blocked by CORS? Here's How to Check CDN Response Headers and Preflight Requests
When a frontend call to an API returns a CORS error, the cause may lie in the origin server, CDN caching, the OPTIONS preflight request, a WAF, or duplicate response headers. This article covers browser and curl checks to help you determine at which layer the cross-origin response headers are being dropped.
Some users cannot access the site after enabling IPv6: Is it a DNS issue or a CDN node issue?
After IPv6 is enabled on a website, users in some regions or on certain carriers may be unable to reach it. The cause may lie in the AAAA record, the user's IPv6 network, a CDN node, TLS, MTU, or IPv6 origin fetch. This article covers DNS, curl, and route testing methods to help determine which layer the failure occurs at.
Origin Server Accessible but CDN Returns 404? How to Troubleshoot Origin Host and Cache
Origin server responding normally, but you get a 404 after putting the CDN in front of it? This article shows you how to tell whether the 404 comes from a CDN node or from your origin, then walks you step by step through troubleshooting origin Host header, port, protocol, caching, URL rewriting, and multi-origin configuration issues.
Are CDNs Right for Dynamic APIs? Distinguish Caching From Dynamic Acceleration
Can dynamic APIs use a CDN? This article explains the differences between API caching, dynamic acceleration, and edge computing, analyzes caching strategies for public endpoints, login endpoints, and GET versus POST requests, and covers Cache-Control, cache keys, security checks, and multi-region speed testing.
How to Choose a CDN for Download Sites: Large-File Speed Tests Need More Than Time to First Byte
When choosing a CDN for a download site, latency and time to first byte are not the only factors. This article explains large-file download speed, sustained throughput, cache hit rate, byte-range chunking, resumable downloads, concurrent downloads, and multi-region speed testing—helping download sites choose a CDN that is genuinely suited to file distribution.