A hosting checker tells you which company runs the servers behind a domain. Most tools start the same way: they resolve the domain to an IP address and look up who owns that IP. They differ in what else they show and in whether you can call them from your own code. This post compares seven tools on both.
Quick Answer: For hosting, content delivery network (CDN), DNS, SSL and WHOIS data in one lookup, use HostingChecker.online or nslookup.io. nslookup.io also lets you pick the DNS resolver. For bulk lookups, HostingChecker.online and WhoHostsThis have free API tiers with paid plans from $9 and $20 per month.
Disclosure: HostingChecker.online is our product. We did not run an accuracy test, so this post has no accuracy scores. Every claim about the other tools comes from their public pages, checked in October 2026. Tools change, so check their sites before you decide.
What makes a good hosting checker tool?
Look at four things:
- What a lookup shows. Some tools show only the provider name. Others add DNS records, SSL certificate details, server location and WHOIS registration data.
- How it handles CDNs. When a site sits behind Cloudflare or another CDN, the public IP belongs to the CDN. A tool that only reads the IP owner reports the CDN as the host. Better tools at least say that a CDN is in the way.
- API access. If you need more than a few lookups, check for an API, its free tier and the price per call.
- Freshness. Live DNS queries show a move to a new host within minutes or hours. Tools that lean on a stored database can lag behind.
The tools we compared
1. HostingChecker.online
What it does: One lookup queries DNS through Cloudflare's 1.1.1.1 resolver (Google's 8.8.8.8 as a fallback), reads the SSL certificate with a live TLS handshake, looks up the IP address with IPinfo, and fetches registration data over RDAP. For registries without RDAP, it falls back to port 43 WHOIS.
What a lookup shows:
- Hosting provider, taken from the autonomous system number (ASN) of the network that owns the IP address
- The CDN in front of the site, the platform (such as Vercel, Netlify or Shopify), the DNS provider, the email provider and the registrar, each with the evidence behind it
- DNS records: A, AAAA, CNAME, MX, NS, TXT, SOA, CAA and SRV
- SSL certificate: issuer, validity dates, days until expiry, the full chain, and whether the chain is trusted and covers the hostname
- IP location: city, region and country
- WHOIS data: registrar, registration and expiry dates, nameservers and status codes
The DNS lookup tool, MX lookup tool, nameserver lookup tool, IP lookup tool, SSL checker and WHOIS lookup tool also have their own pages.
Try it yourself
Check any website's hosting
Enter a domain or IP to see hosting provider, DNS records, and more.
API: The hosting, DNS, SSL, IP and WHOIS lookups are all available over a REST API with a Bearer API key. The Free plan includes 100 API calls per month. Paid plans are Basic ($9 for 5,000 calls), Growth ($29 for 25,000) and Scale ($79 for 100,000), all per month. Lookups on the website need no account and are free, with a per-minute rate limit. See pricing.
Limitations: For a site behind Cloudflare or another CDN, the result names the CDN, but the origin host behind it stays hidden. There is no full technology stack detection, SEO data or IP blacklist check. Results are cached for up to an hour.
2. hostingchecker.com
What it does: Matches the domain's IP against its database of over 5,000 hosting companies, and shows the IP address and server location.
Also shows: Domain age from WHOIS, an IP blacklist check against more than 300 DNS-based blacklists, and a PDF download of the report.
Limitations: The lookup page shows no DNS records or SSL details, and the site lists no API. Some metrics on the page no longer exist: Alexa rank ended when Amazon shut Alexa.com down in 2022.
3. hostingchecker.net
What it does: Shows the hosting provider, IP address, ASN and data center location. It is free, needs no signup and is funded by ads.
Also has: Separate DNS lookup, WHOIS checker, nameserver checker and domain age tools.
Limitations: No SSL details and no API. Its own page says that for a site behind Cloudflare you see Cloudflare, not the origin host.
4. nslookup.io
What it does: A DNS client first. It queries dozens of record types, and you can pick the resolver: popular public resolvers, the domain's authoritative server, or resolvers in other countries. Its hosting checker page shows the provider, IP address, ASN, server location, DNS provider, nameservers, the CDN or proxy provider, the SSL issuer and expiry date, and mail servers.
Also has: A DNS propagation checker, an SSL checker, DNS and SSL monitoring, and a REST API documented at docs.nslookup.io.
Limitations: We found no public API price list. WHOIS lookups are not part of the hosting checker page.
Where it beats us: Its resolver choice is far wider than ours, and it covers more DNS record types.
5. WhoHostsThis (who-hosts-this.com)
What it does: Resolves the domain's IP addresses, checks the WHOIS records for each IP, and cross-references a database of known providers when WHOIS doesn't name one.
API: A free plan with 500 detections at one URL per 10 seconds. Paid plans run from $20 per month for 10,000 detections to $800 per month for 1,000,000.
Limitations: The lookup focuses on the provider name. We did not find DNS records, SSL details or server location on the lookup page.
6. SiteChecker (sitechecker.pro)
What it does: A free hosting checker inside a larger SEO platform. It shows the hosting provider, IP address, server country, region and city, DNS provider, nameservers and web server software. No signup is needed.
Also has: SEO audits, site monitoring and a public API.
Limitations: No full DNS records, SSL details or WHOIS data on the hosting checker page. Most of the platform is paid.
7. BuiltWith (builtwith.com)
What it does: Detects the technology stack of a website: hosting, CMS, frameworks, analytics and more. Single-site lookups on the website are free.
API: A free API with a free account, limited to one request per second. It returns technology group and category totals, not the full hosting details. Paid plans are $295, $495 and $995 per month.
Limitations: No DNS records, SSL details or WHOIS data. BuiltWith is a tool for technology and market research, with hosting as one category.
Feature comparison matrix
"No" means we did not find the feature on the tool's lookup page in October 2026. "Separate tool" means the site has it on another page.
| Tool | Hosting provider | DNS records | SSL details | Server location | WHOIS | API |
|---|---|---|---|---|---|---|
| HostingChecker.online | Yes | Yes | Yes | Yes | Yes | Free tier |
| hostingchecker.com | Yes | No | No | Yes | Domain age | No |
| hostingchecker.net | Yes | Separate tool | No | Yes | Separate tool | No |
| nslookup.io | Yes | Yes | Issuer and expiry | Yes | No | Yes |
| WhoHostsThis | Yes | No | No | No | No | Free tier |
| SiteChecker | Yes | Nameservers | No | Yes | No | Yes |
| BuiltWith | Yes | No | No | No | No | Limited free tier |
API comparison
If you need to automate hosting lookups, compare the free tier and the paid steps:
| Tool | Free tier | Paid plans (per month) |
|---|---|---|
| HostingChecker.online | 100 calls per month | $9 for 5,000, $29 for 25,000, $79 for 100,000 |
| WhoHostsThis | 500 detections, 1 URL per 10 seconds | $20 for 10,000 up to $800 for 1,000,000 |
| BuiltWith | 1 request per second, technology totals only | From $295 |
nslookup.io and SiteChecker document APIs, but we found no public price list for either. hostingchecker.com and hostingchecker.net list no API.
Which tool should you use?
| Use case | Tool |
|---|---|
| Hosting, DNS, SSL and WHOIS in one lookup | HostingChecker.online or nslookup.io |
| Find the CDN in front of a site | HostingChecker.online or nslookup.io |
| Debug DNS across resolvers | nslookup.io |
| Low-cost hosting API | HostingChecker.online or WhoHostsThis |
| IP blacklist check | hostingchecker.com |
| Technology stack research | BuiltWith |
| Hosting data next to an SEO audit | SiteChecker |
Frequently Asked Questions
Are hosting checker tools accurate?
They are accurate about who owns the IP address a domain points to. That owner is not always the host. If a CDN or proxy sits in front of the site, the IP belongs to the CDN. No side-by-side accuracy test went into this post, so it has no accuracy scores for any tool.
Can hosting checker tools detect the host behind a CDN?
Usually not. Cloudflare's proxy answers DNS queries with Cloudflare IP addresses, so the origin server's IP never shows up in public DNS. In that case HostingChecker.online names Cloudflare as the CDN, and the origin host stays unknown. Some clues can remain: MX records can point to the host's mail servers, and a subdomain that isn't proxied can resolve to the origin. Learn more about detecting Cloudflare and identifying CDN usage.
Do I need to pay for a hosting checker?
Not for occasional lookups. Every tool in this comparison has free lookups on its website. You pay for API volume. On HostingChecker.online, the Free plan includes 100 API calls per month, and paid plans start at $9 for 5,000 calls per month.
How do hosting checker tools identify the provider?
They resolve the domain's A and AAAA records to IP addresses. Then they look up who owns each IP, through its ASN and its RDAP or WHOIS registration record. Some tools also match the IP against their own database of hosting companies. For a step-by-step walkthrough, see how to find out who hosts a website.
Wrapping up
For one lookup with hosting, DNS, SSL and WHOIS data, and an API that starts free, use HostingChecker.online. For DNS work across many resolvers, nslookup.io is the stronger tool. For technology stacks, use BuiltWith.
To see the results for yourself, enter any domain into our hosting check.
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Written by
Piotr KulpinskiFounder of HostingChecker.online and a web developer with over a decade of experience in DNS, hosting infrastructure, and domain management. Piotr builds tools that help developers and site owners understand their web stack. Other products: Highseat, OpenAlternative, EuroAlternative, Revinel and Dirstarter.