Website Hosting Checker

Find out who is hosting any website: the web host and the cloud it runs on, the CDN in front, the CMS, who handles the domain's email and where it is registered, each with the evidence behind it. Behind Cloudflare, the platform's own headers, the owner of its address block and the names that skip the CDN can still point to the real host.

Sources: the site's DNS and the network that announces its address (Team Cymru) · the address's regional internet registry · the site's own HTTP headers and markup · Certificate Transparency logs · the domain's registry (RDAP)

What a hosting checker shows

A hosting checker (or host checker) finds the company that stores and serves a website. Type a domain and it looks up the site's IP address, the network that announces that address and who the address block is registered to, then what the site itself gives away: its HTTP headers, the CNAME its www points to, the site builder in its markup and its nameservers. Each signal is weighed, so the answer comes with a confidence and the evidence behind it.

A website is rarely one company. The domain is registered at a registrar, its DNS may run elsewhere, a CDN such as Cloudflare often sits in front, and email often goes to Google or Microsoft. As a domain hosting checker it shows each layer on its own, so "who hosts this site?" gets the answer that was meant.

Hosting checker result: the web host with its evidence, the CDN in front, the registrar, DNS host and email providerHosting checker result: the web host with its evidence, the CDN in front, the registrar, DNS host and email providerThe answerThe web host in one sentence, with its confidence, and the CDN in front when there is one.Every layerRegistrar, DNS host, CDN, web host, the cloud it runs on, and email: each company apart.The evidenceWhy the checker names that host: the network, a platform's own header, a CNAME, the site builder.The detailsEvery address of the domain and of www, the redirect chain, the CMS, the certificate and the mail setup.
A check of a shop behind Cloudflare: the platform named from its own headers, each layer apart and the evidence for each. Select a number to see what each part shows.

How to find out who is hosting a website

There is no public register of hosting customers, so a hosting lookup reads the clues a site leaves in public, from the strongest to the weakest:

  1. 1

    Find the site's IP address

    The domain's A and AAAA records give the address browsers connect to, for the domain and for www, which can differ.

  2. 2

    Find the network behind the address

    A public address is usually announced by one network, an autonomous system with a number (ASN) that a regional internet registry assigned. A hosting company's own network names it: AS47583 is Hostinger, AS53831 Squarespace. A platform that holds its own addresses on a CDN's network is named by the block's registrant: Shopify's addresses are on Cloudflare's network, registered to Shopify.

  3. 3

    Read what the site says about itself

    Platforms label their responses: Kinsta's cache header, WP Engine's X-Powered-By, Vercel's request id. A www that points to shops.myshopify.com, or a site builder's own markup, names the platform too.

  4. 4

    Weigh it, then check the rest

    The nameservers say where the DNS is managed, which is often but not always the host. Signals that agree make a high-confidence answer; several hosts sharing one network make a possible one, with the others listed.

Who serves example-shop.com

  1. RegistrarNamecheap, Inc.Where the domain is registered
  2. DNS hostCloudflareRuns the nameserversada.ns.cloudflare.com · rudy.ns.cloudflare.com
  3. CDN / proxyCloudflareServes visitors in front of the hostASNAS13335headercf-ray: 0000000000000000-FRA
  4. Web hostShopifyStores and serves the websiteHow we know
    • The site answers with the header powered-by: Shopify
    • www points to shops.myshopify.com
    • The page is built with Shopify, which only runs on Shopify
  5. EmailGoogle WorkspaceReceives the domain's mailaspmx.l.google.com +1
From the domain down: Registrar · DNS host · CDN / proxy · Web host · Email

Web host, registrar, DNS host and CDN: who does what

Four or five companies can stand behind one website, and "hosting" means a different one to each person asking. Here is what each does and how the checker finds it:

LayerWhat it doesHow the checker finds itExample
RegistrarSells and renews the domain name and sends its nameservers to the registry.The registry's RDAP recordGoDaddy, Namecheap
DNS hostAnswers DNS queries for the domain: where the site, mail and subdomains are.The NS recordsCloudflare, Route 53
CDN / proxySits in front of the host, caches pages near visitors and filters attacks. Visitors connect to it, not to the host.Its network and its own headers (cf-ray, Via)Cloudflare, Fastly
Web hostStores the website's files and database and runs its code.The address's network and block registrant, platform headers, CNAMEs, the site builderSiteGround, Kinsta, Shopify
Runs onThe cloud a platform rents its servers from.The address's networkGoogle Cloud, AWS
EmailReceives the domain's mail.The MX recordsGoogle Workspace, Microsoft 365

Why does a hosting checker say Cloudflare?

Because Cloudflare is the company visitors connect to. When a site's DNS record is proxied through Cloudflare, the domain resolves to Cloudflare's addresses and Cloudflare fetches the pages from the real host out of sight. Fastly, Amazon CloudFront and Akamai do the same, usually through a CNAME to the CDN's own hostname, which stays visible in DNS. A checker that only reads the IP address then calls Cloudflare the host, which is true for the traffic and wrong for the hosting.

This checker names the CDN as its own layer and keeps looking: a platform's own headers usually pass through the CDN, and the registrant of the address block can name the platform, so Shopify, Kinsta or Vercel are still found behind it. A record Cloudflare proxies hides its CNAME, though.

Clues to a host behind a CDN

  • Names that skip the CDN

    On cPanel hosting, cpanel. and webmail. point straight at the host's server, and mail. or ftp. often do. The result names the network they are on.

  • The mail setup

    MX records at the host's mail servers, or an SPF record that allows the host to send, point to it.

  • The nameservers

    A site on Hostinger's or SiteGround's nameservers is often hosted there, even with a CDN in front.

  • Ask the owner

    Only the site's owner and the CDN know the origin for sure.

We name networks, never a hidden server's address: that address is what lets attackers go around a CDN's protection.

Find who hosts a website with dig, whois and curl

The same lookups from a terminal, on macOS and Linux (Windows: nslookup and PowerShell's Resolve-DnsName for the DNS steps). Put the site's name in place of example.com and its address in place of 203.0.113.10:

To findCommand
The site's addressdig +short example.com A
The network behind itwhois -h whois.cymru.com " -v 203.0.113.10"
Who holds the address blockwhois 203.0.113.10
The headers it sendscurl -sI https://example.com
Where www pointsdig +short www.example.com CNAME
The nameserversdig +short example.com NS
The mail serversdig +short example.com MX

Behind a CDN the address and network are the CDN's: read the headers, and the block's registrant, which names a platform that holds its own addresses.

How do I find out who hosts my own website?

Check your domain above: the web host and the registrar each come with a link to their login page. If the host is hidden behind a CDN, these find it:

  1. 1

    Search your inbox

    Look for invoices and renewal notices: "hosting", "cPanel", "renewal", or the domain itself.

  2. 2

    Check the registrar

    The registrar often sells hosting too, and its dashboard shows the nameservers, which lead to the DNS host.

  3. 3

    Open the CDN's dashboard

    In Cloudflare, the domain's DNS records show each proxied record's real target, the origin's address or hostname. IP Lookup turns an address into a company.

How accurate is a hosting checker?

As accurate as the clues a site leaves. Each answer carries one of three ratings:

  • High confidence

    The address is on the host's own network, or the platform's own header, CNAME or address block names it, and nothing contradicts that.

  • Likely

    One good signal names the host, or a CDN in front means the address's network can't be checked.

  • Possible

    Only weaker signals agree, such as the nameservers, or several hosts share the same network (Bluehost and HostGator often do). The others are listed.

A reseller or an agency that rents space from a bigger host shows as that host: the network can't tell them apart.

Hosting checker API

A free endpoint with CORS for browsers: POST a domain or GET it in the query. The answer has the fields of our older API plus the layers, addresses, redirects, hints and certificate shown here. 10 checks a minute per network; a repeat within the hour comes from cache.

POST /api/hosting-check
$ curl -X POST https://dnsrobot.net/api/hosting-check \
    -H "Content-Type: application/json" -d '{"domain": "allbirds.com"}'
{
  "domain": "allbirds.com", "state": "hosted",
  "host": { "slug": "shopify", "name": "Shopify", "confidence": "high", "evidence": [ … ] },
  "cdn": { "slug": "cloudflare", "name": "Cloudflare", … },
  "cms": ["Shopify"], "emailProvider": "Microsoft 365", "registrar": "MarkMonitor Inc.", …
}

Hosting Checker FAQ

How do I find out who is hosting a website?

Type the domain into the hosting checker above. It looks up the site's IP address, the network that announces it and who the address block is registered to, then reads the site's own HTTP headers, its CNAME records, its markup and its nameservers, and names the host with a confidence and the evidence. To check hosting by hand: find the address with dig, its network with Team Cymru's whois, the block's holder with whois, and the headers with curl.

Why does the hosting checker say Cloudflare?

Because the site is behind Cloudflare's proxy: its domain resolves to Cloudflare's addresses, and Cloudflare fetches the pages from the real host. Cloudflare is the CDN, not necessarily the host. This checker shows Cloudflare as the CDN layer and looks for the platform behind it in the headers that pass through and in the address block's registrant.

Can I find the real host of a website behind Cloudflare?

Sometimes. A platform's own headers often still name it, and so can the registrant of the address block; names like cpanel. or webmail. often point straight at the host's server, and the result names its network. When nothing leaks, the host stays hidden: only the owner and Cloudflare know it. We never show a hidden server's address, because that would help attacks get around the CDN.

Is the web host the same as the domain registrar?

Not always. The registrar is where the domain name is registered and renewed; the web host stores and serves the site. Many companies do both, but a domain from Namecheap can point to a site on SiteGround, with its DNS at Cloudflare. The result shows the registrar, the DNS host and the web host as separate layers.

How can I tell which WordPress host a site uses?

Managed WordPress hosts label their responses: Kinsta, WP Engine, WordPress VIP, Pantheon and others add their own headers, which usually pass through a CDN (a site can remove them). On shared hosting the address's network names the host. The CMS row shows WordPress when the markup gives it away.

How do I find where a website's server is located?

Often you can't, and most tools that claim to are guessing. A CDN answers from a location near the visitor, and an IP address's country in registry data is the country of the organisation the block is registered to, not where the server stands. The result shows the CDN location that answered and the block's country, and says which is which.

How can I tell who hosts a website's email?

From its MX records, the servers that receive its mail: smtp.google.com (or the older aspmx.l.google.com) means Google Workspace, *.mail.protection.outlook.com Microsoft 365. The result names the provider behind the MX hosts and lists the services the domain's SPF record allows to send mail, such as Microsoft 365 (include:spf.protection.outlook.com) or Amazon SES.

What is an ASN, and how does it identify the host?

An ASN is the number of an autonomous system: a network that announces blocks of IP addresses, its own and sometimes its customers'. IANA hands ASNs to the five regional internet registries, which assign them to operators. Hosting companies and clouds run their own, so the network carrying a site's address usually names the host: AS16509 is Amazon, AS47583 Hostinger. When a platform's addresses ride on a CDN's network, the block's registrant names it instead.

How accurate is the hosting checker?

Very, when the signals agree: a host's own network or a platform's own header is hard to fake by accident. Each answer is rated High confidence, Likely or Possible, with the evidence listed, and hosts that share one network are named together. A reseller renting space from a bigger host shows as the bigger host.

Is this web hosting checker free, and do you keep what I check?

It's free, with no account; one network can run 10 checks a minute. The check runs on our server, so the site sees our visit, not yours. An answer is kept for an hour so repeat checks are fast, then dropped. We don't log who checked what.

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