What is the difference between a host and a root domain?

The host is the full name in the URL, like shop.example.co.uk. The root (registrable) domain is the part a company registers, example.co.uk. Email usually runs on the root domain.

Does it handle international domains?

Yes. Domains with accented letters are converted to their ASCII (punycode) form, which is how DNS and mail servers see them.

Does it check that the domain exists?

No. It reads the text only. To see whether a domain is registered and receives mail, run it through the bulk DNS or email provider lookups.

No. It is read in your browser and nothing is sent anywhere.

Extract the domain from a list of URLs or websites

In short: Turns https://www.example.com/about?utm=x, example.com/contact or an email address into example.com in bulk, with the root domain for subdomains (co.uk-aware), and flags rows that have no company domain: social profiles, link-in-bio pages, Shopify, Wix and other hosted subdomains, IPs and names. Limit: Root domains use a short list of two-part endings, not the full Public Suffix List.

Paste a list of URLs, or a CSV with a website column, and press Extract domains. The protocol, www, path, query and UTM tags are removed, subdomains are reduced to the root domain (shop.example.co.uk becomes example.co.uk), and rows that can't stand in for a company domain, such as LinkedIn profiles or myshopify.com stores, are flagged.

Price: this tool is free. Checking a whole email list is from $9/mo, and the first 100 checks are free with Google, no card. See pricing

URLs or websites one per line, or a CSV with a website column

Upload a CSV or TXT fileRuns in your browser. Nothing is uploaded.

Root domain only (shop.example.co.uk becomes example.co.uk); untick to keep subdomains

SimpleAPI

Sample result

8 websites read: 5 domains, 1 LinkedIn profile, 1 Shopify-hosted store and 1 name that isn't a URL.

Domains: 5
Profiles: 1
Hosted sites: 1

What this means for you

Use the 5 domains to find addresses; the other 3 rows need a real company website.

Next step:Find the email format

https, www, paths and UTM removed
Subdomains to the root domain
Social profiles flagged
Shopify and Wix subdomains flagged

Domains
Websites
CSV

By SimpleVerifier Team · Last updated November 2, 2026 · Runs in your browser; nothing you paste is sent to us

How do I check the email addresses at these domains?

Use the domains here to find or guess addresses, for example with the email format finder.
Upload the address list at /verify. Every address gets a live mailbox check, and valid, risky and invalid download as separate files. The first 100 email checks are free with a Google sign-in, no card.
Send only to the valid file.

Check the list

How do I extract domains from a list of URLs?

Export the list with its website column (Apollo, Clay, HubSpot and Google Maps scrapes all have one).
Paste it here or upload the CSV. The website column is found by its name, or by which column holds URLs.
Choose root domain only, or keep subdomains, and press Extract domains.
Download the CSV with the domain column added, or copy the unique domains.

Example

You enter: 8 rows with a website column: a www URL with a UTM tag, a bare domain, http://shop.fabrikam.co.uk/cart, an email address, a LinkedIn company page, a myshopify.com store, www.litware.example/ and the name Proseware Inc.
You get: 5 domains (northwind.example, contoso.example, fabrikam.co.uk from the subdomain, adatum.example from the address, litware.example), 1 profile (LinkedIn), 1 hosted site (myshopify.com) and 1 that isn't a URL.
Limits: Runs in your browser with no row cap; an uploaded file can be up to 25 MB.

How do I extract a domain from a URL in Excel or Google Sheets?

In Google Sheets, =REGEXEXTRACT(A2, "^(?:https?://)?(?:www\.)?([^/:?#]+)") returns the host for most URLs. In Excel, nested SUBSTITUTE and LEFT/FIND formulas do the same job more clumsily. Both stop at the host, so shop.example.co.uk stays a subdomain, and neither notices that linkedin.com/company/acme isn't the company's website.

This tool does the host step, then reduces subdomains to the registrable domain using a list of two-part endings (co.uk, com.au, co.jp and similar), and says what each odd row is, so you can fix the source instead of guessing.

Which rows don't give a company domain?

Social and directory profiles (LinkedIn, Facebook, Instagram, X, Yelp, Google Maps links, Linktree), because the domain belongs to the platform. Site-builder addresses such as acme.myshopify.com, acme.wixsite.com or acme.webflow.io, because the company has no domain of its own there and no mailbox at it. Bare IP addresses, and cells that hold a company name rather than a URL.

Emails in the website column are read too: jane@example.com gives example.com, marked as taken from an address. Personal mail domains like gmail.com aren't a company domain either; the free vs business email filter separates those.

Who uses this tool, and for what?

Cold emailers: Turn an Apollo or Clay website column into domains for an email finder or permutator.
Lead generation: Clean a Google Maps scrape where half the websites are Facebook pages or Linktree links.
RevOps: Normalise account websites to one domain per company before deduplicating or matching to CRM records.
SEO and outreach: Reduce a list of page URLs to the unique sites they belong to.

What can’t this tool tell you?

Root domains use a short list of two-part endings, not the full Public Suffix List.
It doesn't look up DNS, so a domain that no longer exists still comes back.
It can't tell whether a company domain is the one its staff use for email.
It can't tell whether any address at the domain exists.

Common questions

What is the difference between a host and a root domain?: The host is the full name in the URL, like shop.example.co.uk. The root (registrable) domain is the part a company registers, example.co.uk. Email usually runs on the root domain.
Does it handle international domains?: Yes. Domains with accented letters are converted to their ASCII (punycode) form, which is how DNS and mail servers see them.
Does it check that the domain exists?: No. It reads the text only. To see whether a domain is registered and receives mail, run it through the bulk DNS or email provider lookups.
Is my list uploaded?: No. It is read in your browser and nothing is sent anywhere.

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 — $39/mo See the published limits first

Plans from $9 a month, 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.