Effects on search visibility.
WHAT HELPS
Faster pages, which is a modest ranking factor and a real conversion factor Better availability under load HTTPS, which a CDN makes straightforward
WHAT CAN HURT
Blocking search engine crawlers by accident, through an aggressive security setting or a firewall rule Serving stale content long after it changed A misconfiguration making the site unavailable
CHECKING CRAWLERS ARE NOT BLOCKED
Cloudflare's security events log shows challenged and blocked requests with their user agents.
If crawler traffic appears there, your site is being crawled less than it should be.
Allow known crawlers explicitly.
CACHE DURATION
Very long cache times on HTML mean search engines may see outdated content.
Purge after significant changes.
DUPLICATE CONTENT
A CDN serving assets from another hostname does not create duplicate content, since only assets are affected.
Caching HTML at a different hostname would, which is why you do not do that.
AFTER ENABLING A CDN
Check Search Console for crawl errors over the following weeks.
A sudden rise in crawl failures usually means the CDN is blocking something.
