Serving through a CDN: Crawl Audit check 92

Short answer: a content delivery network (CDN) keeps copies of your files on servers around the world, so each visitor is served from somewhere near them. That cuts the wait for every request. Check 92 passes when your response headers show a known CDN, and warns when they don't.

What Crawl Audit checks

• Crawl Audit looks through your homepage's response headers for the names or headers of common CDNs and edge hosts: Cloudflare, Vercel, Fastly, Akamai, Netlify, CloudFront and Sucuri, plus headers such as cf-ray and x-served-by.
• Pass: one is found. Warning: none found.

The list is Crawl Audit's own. A CDN that doesn't announce itself in headers, or isn't on the list, gets a warning even though it's there.

What Google says

• web.dev: "CDN servers are located closer to users than origin servers and therefore have a shorter round-trip time (RTT) latency".
• "a resource's Time to First Byte (TTFB) can be significantly improved when introducing a CDN" (check 71).
• "CDNs are particularly effective at improving LCP" (check 72).
• CDNs also tend to bring fast DNS (check 93) and modern protocols such as HTTP/2 or HTTP/3 (check 94).

On devmarde.com

Our responses carry Server: Vercel and an x-vercel-id header naming the edge location that served them, so this passes.

On your platform

• Shopify, Wix, Squarespace, Vercel and Netlify serve through a CDN as standard. "Wix uses CDN - a system of global cache services and proxy servers."
• WordPress on ordinary hosting: add a CDN such as Cloudflare in front of the site, or use your host's built-in one.

Sources

• web.dev, Content delivery networks (CDNs) and Optimize Time to First Byte, checked 3 October 2026.
• Wix, How Wix improves a site's loading time.