Free domain lookup tools: age, owner, host and mail provider
No code. Paste a domain, or a list of them, and see its age, registrar, host and email provider.
Look up who a domain belongs to and what it runs on: whether it is free to register, how old it is, when it expires, what its status codes mean, its registrar, web host and status, whether it has DNSSEC, CAA and IPv6, its security headers, robots.txt, sitemap, favicon, security.txt, ads.txt and llms.txt, whether www and HTTPS redirect to one address, who runs its extension, how an internationalised name is written in Punycode, which mailbox provider and email tools it uses, and look-alike domains that could be used to spoof it. Most run in bulk on a pasted list of domains.
35 free tools
Bulk domain availability checker
Paste up to 100 domains (500 when signed in), or bare names to try across .com, .io and other TLDs, and see which are registered and which look available, straight from each registry's RDAP server.
Domain age checker
Registration date, age, expiry and registrar for up to 10 domains, read from each registry's RDAP server, with honest gaps where a registry publishes nothing.
Bulk domain age checker
Paste or upload a list of domains or emails and get each domain's creation date, age and registrar from RDAP, sorted, filtered by age and downloadable.
Bulk domain expiry checker
Paste or upload a list of domains and get each one's expiry date, days left and registrar from RDAP, grouped into expired or in grace, under 30 days, 30–90 days and 90+ days.
Domain drop date calculator
Enter a domain or a list. Each one's registry status and expiry date give its phase and the window in which it could be deleted and released.
Available domain name generator
Enter up to three keywords and pick TLDs: name ideas from prefixes, suffixes and keyword joins are checked against each registry's RDAP server and DNS, likely-available first.
Domain extension checker
Type one name and check it across up to 52 extensions in five groups (popular, tech, business, brand and country), with each registry's answer: likely available, registered or unknown.
Domain hack generator
Enter words or a brand name and see every way the word's ending can be a domain extension (market.ing, brew.ing, delicio.us), each checked against its registry: likely available, registered or unknown.
Domain transfer checker
Paste domains and see which can move to another registrar now, which need the registrar lock turned off, which are inside the 60-day window (with the date it ends) and which are blocked by the registry.
Domain status code checker
Paste domains and get every EPP status code in each registry record, explained: who set it, what it does, and what to do, with each domain read as Normal, Needs a look, On hold or Being deleted.
WHOIS lookup
Registrar, creation and expiry dates, EPP status, name servers and DNSSEC from the registry's own RDAP server, with contact records hidden until you ask.
Bulk WHOIS lookup
Paste or upload domains and get registrar, created, updated and expiry dates, EPP status codes, nameservers and DNSSEC for each, from the registry's RDAP server, in one table.
Domain registrar lookup
Enter a domain or a list and get each one's registrar and expiry from the registry, the company that runs its DNS (where records are edited) and its email provider.
Website host checker
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.
Bulk website status and parked domain checker
Paste a list of domains and see each one's HTTP status, where it redirects, and whether it looks parked or for sale, with the signal that says so.
Bulk SSL certificate checker
Paste domains or host names and get each one's TLS certificate: days left, expiry date, issuer, the names it covers, and whether it's expired, for the wrong name or not trusted.
DNSSEC checker
Paste one domain or a list and see which are signed and validate, which are broken (validating resolvers refuse them), which have keys but no DS at the registry, and which aren't signed.
CAA record checker
Paste domains or host names and see, for each, the CAA record a CA would use (its own or a parent's), the CAs allowed for ordinary and wildcard certificates, and where refusals are reported.
IPv6 checker
Paste domains and see, for each, whether the website (the domain and www), the MX mail servers and the name servers publish IPv6 addresses: IPv6 ready, Partly or IPv4 only.
Security headers checker
Paste websites and see, for each home page, whether Strict-Transport-Security, Content-Security-Policy, clickjacking protection and nosniff are set, and which are weak.
Robots.txt checker
Paste websites and see, for each, whether robots.txt lets Googlebot, Bingbot and the main AI crawlers (GPTBot, ClaudeBot, PerplexityBot, CCBot...) fetch the home page, plus its Sitemap lines.
Sitemap checker
Paste websites and see, for each, where its sitemap is (robots.txt or /sitemap.xml), whether it's a sitemap or an index, how many URLs it lists and whether it's over the limits.
Favicon checker
Paste websites and see, for each, the favicon and Apple touch icon its home page declares (or /favicon.ico), whether each loads as an image, and its format and size.
Punycode converter
Paste domains with accents or non-Latin letters, or xn-- names, and get both forms, the length DNS sees, and warnings for invalid characters and mixed scripts.
Security.txt checker
Paste websites and see, for each, whether /.well-known/security.txt exists, has the required Contact and Expires fields, hasn't expired and follows RFC 9116, with every contact listed.
Ads.txt checker
Paste publisher domains and see, for each, whether /ads.txt exists, how many DIRECT and RESELLER records it has, which ad systems it names, its OWNERDOMAIN and MANAGERDOMAIN, and every line a buyer's crawler will skip.
Llms.txt checker
Paste websites and see, for each, whether /llms.txt exists, whether it's Markdown with the H1, blockquote summary and linked H2 sections the llmstxt.org proposal describes, how many links it lists, and whether /llms-full.txt exists.
WWW redirect checker
Paste domains and see, for each, where http://, https://, http://www. and https://www. end up, the redirect codes on the way, and whether the site is Consistent, uses temporary redirects, has one version that fails, is split into two copies, or doesn't send visitors to HTTPS.
TLD registry lookup
Paste extensions, domains or URLs and see, for each top-level domain, its sponsoring organisation and technical contact's organisation from IANA's root zone records, when it entered the root, whether it's DNSSEC-signed, and whether its registry offers RDAP for domain lookups.
Lookalike domain checker
Enter your domain to generate up to 150 typo, homoglyph, Unicode and TLD variants and see which are registered, which answer on the web and which have MX records to send or receive email.
Email provider lookup
Enter a domain or address and see its mail provider and any security gateway (Proofpoint, Mimecast, Barracuda), read from MX and SPF records.
Bulk MX / provider lookup
Upload a CSV of emails or domains, get each row's mail provider from MX and SPF, and download the list split into Google, Microsoft and other.
Email stack lookup
Paste company domains and see each one's mailbox provider, sending platforms, security gateway, DMARC reporting and verified SaaS, with the DNS record behind each.
Which ESP sent this email?
Paste the raw headers of any email and see the platform that sent it, such as SendGrid, Mailchimp or Amazon SES, with the DKIM, bounce and Received lines behind it.
Is Gmail down?
Reads Google's own status feed for open Gmail incidents and connects to Gmail's mail servers to read their greeting, with the time of each check. Outlook.com too, from Microsoft's status page.