Cloudflare Custom Error Page Crawler
Cloudflare Custom Error Page Crawler is an SEO crawler operated by Cloudflare. It maps link graphs, ranking signals, and on-page audits, usually for a SaaS product that helps marketers monitor their own or competitor sites.
Volume can be heavy. SEO crawlers often request every page on a site, and several can hit you in parallel if multiple customers are auditing your domain at once.
Most are well-behaved, respect robots.txt, and back off when rate-limited. The trade-off for allowing them is being visible inside the marketing tools your customers and competitors use.
See Cloudflare Custom Error Page Crawler on your own site
Match the User-Agent header on incoming requests against the pattern below.
regex
For higher confidence, also verify the source IP against the operator's published ranges. UA strings can be spoofed; IP ownership is harder to fake.
The polite way is a robots.txt rule. Compliant agents respect it; the others ignore it.
robots.txt
Test a URL
Paste any URL on your site and we'll fetch its robots.txt to check whether Cloudflare Custom Error Page Crawler is allowed.
Renders JavaScript
No
IP verification
Published IP ranges
Crawl frequency
Heavy on demand
Honors robots.txt
Yes
Honors Crawl-delay
Yes
Cloudflare runs 35 bots in total. Each one is a separate user-agent so you can allow or block them independently.
DevOps & Monitoring
10SEO Crawler
6- Cloudflare Digicert DCV
- Cloudflare Custom Error Page CrawlerYou are here
- Cloudflare Healthchecks
- Cloudflare Prefetch
- Cloudflare Purge
- Cloudflare SSLDetector
CDN Infrastructure
5Training Crawler
4Security Scanner
3AI Search Index
2Link Unfurler
2Generic Crawler
2Task Automation
1Should I let Cloudflare Custom Error Page Crawler through?
In most cases, yes. Useful to be visible in SEO tooling, but volume can be heavy. Rate-limit to keep the load manageable. If volume gets noisy, rate-limit it before you block it outright.
Does blocking Cloudflare Custom Error Page Crawler affect my Google rankings?
No. Cloudflare Custom Error Page Crawler is not a search-engine crawler. Your ranking on Google or Bing is unaffected by what you do here.
How do I confirm a request is really from Cloudflare Custom Error Page Crawler?
Look at the User-Agent header in your access logs and match it against the strings listed above. Worth knowing that the User-Agent is easy to fake, so this check tells you "the traffic claims to be Cloudflare Custom Error Page Crawler", not "the traffic is genuinely Cloudflare Custom Error Page Crawler". If you need stronger guarantees, look for a reverse-DNS check or wait for Cloudflare to publish IP ranges.
Why is a third-party tool crawling my site?
Someone, possibly a competitor running a backlink audit, possibly your own team, set up a job in Cloudflare. The crawler runs on their schedule. Blocking it only blocks their visibility into your site, it doesn't break anything user-facing.
How is Cloudflare Custom Error Page Crawler different from Cloudflare's other bots?
Cloudflare splits work across multiple user-agents so site owners can decide on each one independently. Training crawlers, live-fetch agents, search indexers, and agentic browsers each get their own name. Worth scanning the rest of the Cloudflare family above to see which ones actually matter for your site.
What's the cleanest way to control Cloudflare Custom Error Page Crawler?
Two layers. Robots.txt for the polite crawlers that read it, and rules at your CDN or edge for the ones that don't. Rankly's Agent Experience handles both from a single config, so you can allow, block, rate-limit, or serve a stripped-down version per bot. Agent Analytics handles the observation half so you know which bots are actually worth a rule.
Verify everything above against the operator's own documentation.