How can I tell what platform a website is built on?

Check the DNS records and response headers. Platforms publish the exact CNAME or A record customers add, and many label their responses, such as server: Vercel or x-shopid for Shopify. This tool matches both and shows which one matched.

Can I check who hosts many websites at once?

Yes. Paste up to 100 domains a run without an account, or 500 after a free Google sign-in. Each row shows the platform, the evidence, the DNS host and the email provider, and everything downloads as CSV.

Why does a site show as not recognised?

Its records and headers don't match a platform we fingerprint. That usually means its own servers, a general cloud server or a smaller host. We list the IP addresses and CNAMEs we saw rather than guess.

Can it find the real server behind Cloudflare?

No. Cloudflare's proxy hides the origin by design, and this tool doesn't try to get around that. It names Cloudflare and any platform header that still comes through.

Does the checker visit the website?

It makes one GET request to the home page and reads only the response headers, without following redirects or reading the page. Everything else is a DNS lookup.

Website host checker: who hosts this website?

In short: Paste one website or a list and see which platform serves each one, the DNS record or header that says so, plus the company running its DNS and its email. Limit: A site behind Cloudflare or another CDN hides its real host, so the checker can name the CDN but often not the server behind it.

A website host checker tells you which platform serves a site. Enter a domain or paste a list: each one's CNAME and A records and the headers of one request to its home page are matched against the setups Vercel, Shopify, Wix, Squarespace, Netlify and others publish. You also see who runs its DNS and its email.

Websites or domains, one per line (up to 100)

Upload a CSV or TXT fileDNS lookups and one request to each home page. 100 domains a run, or 500 when you sign in.

By SimpleVerifier Team · Last updated October 26, 2026

How do I check which platform hosts a website?

Enter a domain or website address, or paste a list, one per line. Email addresses and full URLs are reduced to their domain.
Press Find the host. For each domain we read its CNAME (and the www CNAME), its A records, its NS and MX records, and the headers of one GET request to the home page.
Read the platform for each site with the exact record or header behind it. A site behind Cloudflare or another CDN is shown as such when its origin is hidden.
Download the results as CSV, with the evidence, IP addresses, DNS host and email provider for every domain.

Example

You enter: The domain shop.example, whose www CNAME is shops.myshopify.com and whose home page answers with an x-shopid header, behind Cloudflare.
You get: Hosted on Shopify, via Cloudflare: the CNAME and the x-shopid header both name Shopify, and the cf-ray header shows Cloudflare in front. The row also names the DNS host from NS and the email provider from MX.
Limits: Up to 100 domains a run without an account and 500 when signed in with Google, 25 per request. DNS lookups and one GET per home page (headers of the first response only); no email is sent.

How do I find out who hosts a website?

Look at what the domain points to. Hosting platforms tell customers to add a specific record when they connect a domain: Vercel's domain docs give the A record 76.76.21.21 and a CNAME to cname.vercel-dns.com, GitHub Pages gives four 185.199.108–111.153 addresses, and Shopify, Squarespace, Wix, Netlify and Webflow publish theirs. This checker reads those records and names the platform when one matches.

Many platforms also label every response they serve. Vercel sends server: Vercel, Netlify sends server: Netlify, GitHub sends server: GitHub.com, and Shopify adds an x-shopid header. The checker makes one request to the home page, reads the headers of the first response and stops there: no page body is read and no redirect is followed.

Why does it say the site is behind Cloudflare?

Because Cloudflare's proxy sits in front of the real server and answers for it. When a domain's A records fall in Cloudflare's published IP ranges or the response carries a cf-ray header, the visitor talks to Cloudflare, and the origin host behind it is hidden on purpose. The checker says so rather than guessing. If a platform header still comes through (Shopify behind Cloudflare is common), the host is named as well.

A domain can also point at a CDN such as Amazon CloudFront, Fastly or Akamai. Those are shown as the CDN in front of the site; the host behind a CDN is only named when another record or header gives it away.

Is the website host the same as the email provider?

Often not. The website and the mail for one domain usually run at different companies: a site on Shopify or Vercel with mail on Google Workspace or Microsoft 365 is the normal setup. Mail is decided by the domain's MX records, so each row also names the mail provider from MX, and the company that runs the DNS from the NS records. To see every service a company uses for email, run the email stack lookup.

Is this quicker than reading the DNS records yourself?

	This tool	dig or nslookup
Domains per run	Up to 100, or 500 signed in	One query at a time
Records matched to a platform	Yes, with the evidence	You look up each value
Response headers read	Yes, first response only	Needs curl as well
DNS host and email provider	In the same row	Separate NS and MX queries

Who uses this tool, and for what?

Founders: Just connected a new domain to Shopify, Squarespace or Vercel? Check the records point where the platform says, then check the domain's email setup.
Agencies: Pull the platform behind every prospect's site in one CSV, so the pitch fits the stack they actually run.
Sales ops: Segment an account list by website platform (Shopify stores, Webflow sites) next to its mail provider.
Developers: Confirm a DNS change went through: after moving a site, the CNAME and the server header should name the new host.

What can’t this tool tell you?

A site behind Cloudflare or another CDN hides its real host, so the checker can name the CDN but often not the server behind it.
Only platforms with a published record or a standard header are named; self-hosted servers and smaller hosts show as not recognised.
One request per home page: a site that blocks automated requests or times out is judged on its DNS records alone.
The website host says nothing about whether an email address on the domain exists.

Common questions

How can I tell what platform a website is built on?: Check the DNS records and response headers. Platforms publish the exact CNAME or A record customers add, and many label their responses, such as server: Vercel or x-shopid for Shopify. This tool matches both and shows which one matched.
Can I check who hosts many websites at once?: Yes. Paste up to 100 domains a run without an account, or 500 after a free Google sign-in. Each row shows the platform, the evidence, the DNS host and the email provider, and everything downloads as CSV.
Why does a site show as not recognised?: Its records and headers don't match a platform we fingerprint. That usually means its own servers, a general cloud server or a smaller host. We list the IP addresses and CNAMEs we saw rather than guess.
Can it find the real server behind Cloudflare?: No. Cloudflare's proxy hides the origin by design, and this tool doesn't try to get around that. It names Cloudflare and any platform header that still comes through.
Does the checker visit the website?: It makes one GET request to the home page and reads only the response headers, without following redirects or reading the page. Everything else is a DNS lookup.

Sources

A tidy list can still be full of dead addresses.

Extracting, deduplicating and syntax checks all work on the text of an address. None of them can tell whether the mailbox exists. Only the server that hosts it can answer that, through an SMTP check, and that is what the paid product does.

Upload the cleaned file as it is: CSVs up to 100,000 rows
A real SMTP mailbox check on every row, with catch-all detection
Small list? Starter at $9/mo covers 2,500 emails a month, cancel anytime

Get started — $29.99/mo See the published limits first

One plan, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.