Cloudflare at a Glance
| Type | CDN and reverse proxy |
|---|---|
| Website | www.cloudflare.com |
| Network (ASN) | AS13335 CLOUDFLARENET, AS209242 CLOUDFLARESPECTRUM |
| Announced IP space | 2,719 IPv4 prefixes (~2,634,240 addresses), 3,066 IPv6 prefixes |
| Customer nameservers | None: keep your DNS provider and add the records from the dashboard |
Cloudflare Nameservers
Cloudflare does not ask customers to move their nameservers. Your domain stays with its current DNS provider, and you point it at Cloudflare with the A, AAAA or CNAME record shown in your Cloudflare dashboard. Verify the record afterwards with the DNS lookup.
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Cloudflare IP Ranges and ASN
Cloudflare announces its address space from 2 autonomous systems. Any website whose IP address falls in these ranges runs on Cloudflare's network, or is proxied through it. Counts are from the global routing table on September 25, 2026.
| ASN | Registered name | Registry | IPv4 prefixes | IPv4 addresses | IPv6 prefixes |
|---|---|---|---|---|---|
| AS13335 | CLOUDFLARENET - Cloudflare, Inc., US | arin · since 2010 | 2,440 | 2,529,280 | 3,038 |
| AS209242 | CLOUDFLARESPECTRUM - Cloudflare London, LLC, US | ripencc · since 2019 | 279 | 104,960 | 28 |
Largest Cloudflare IP blocks
104.16.0.0/12152.114.0.0/17150.48.128.0/18152.114.128.0/18204.195.192.0/18104.18.32.0/19104.21.0.0/19104.21.32.0/192a0a:6c80::/292a09:bac1::/3268.169.48.0/2069.89.0.0/20216.154.208.0/2066.94.40.0/21154.84.16.0/21194.39.112.0/215.10.244.0/2245.131.4.0/222a05:7880::/322a06:9ac0::/32Look up any address in these blocks with the IP lookup or the ASN lookup.
How to Check if a Website Is Hosted on Cloudflare
Enter the domain in the checker at the top of this page. It names Cloudflare when one or more of these signals match, and lists each one as evidence:
- The site's IP address is inside AS13335 or AS209242, the network Cloudflare announces.
- The HTTP response carries an cf-ray header or a server header matching Cloudflare.
- For a CDN, the IP address and headers such as cf-ray or server show the proxy, not the origin host. The checker reports Cloudflare as the CDN and keeps looking for the real host.
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Cloudflare FAQ
What are Cloudflare's nameservers?
Cloudflare does not ask customers to switch nameservers. You keep DNS at your registrar or DNS provider and add the A, AAAA or CNAME record shown in your Cloudflare dashboard.
What is Cloudflare's ASN?
Cloudflare announces its IP addresses from AS13335 (CLOUDFLARENET, registered with ARIN) and AS209242 (CLOUDFLARESPECTRUM, registered with RIPENCC).
How many IP addresses does Cloudflare have?
As of September 25, 2026, Cloudflare's network announces 2,719 IPv4 prefixes covering about 2,634,240 IPv4 addresses, plus 3,066 IPv6 prefixes (source: RIPEstat routing data).
How can I tell if a website is hosted on Cloudflare?
Run the domain through the hosting checker on this page. It reports Cloudflare when the site's IP address is inside AS13335 or AS209242, the network Cloudflare announces, and it shows every matching signal as evidence.
Is Cloudflare a web host or a CDN?
Cloudflare is a cdn and reverse proxy: it provides a CDN and reverse proxy, DNS, DDoS protection, Workers and Pages hosting.
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Cloudflare is a trademark of its owner. DNS Robot is not affiliated with Cloudflare unless an offer above is marked sponsored.