IPv6 checker: does this domain work over IPv6 for web, email and DNS?
In short: 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. Limit: DNS only: it doesn't connect to the IPv6 addresses, so firewalls or broken routes don't show.
An IPv6 checker tells you whether a domain can be reached over IPv6. Paste one domain or up to 100 (500 after a Google sign-in): for each, the checker looks up AAAA (IPv6) and A (IPv4) records for the domain and www, its mail servers and its name servers, and reports Website, Mail and DNS as Yes, Partly or No, with an overall IPv6 ready, Partly IPv6 or IPv4 only.
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
Sample result
acme.example's mail and DNS have IPv6, but its website is IPv4 only.
- Domain
- acme.example
- Website
- No
- Yes
What this means for you
See which part of each domain still lacks IPv6: the site, the mail servers or the DNS.
- Domain and www, MX hosts and name servers
- Non-public AAAA values flagged
- DNS only, nothing connects to the domain
- 100 domains a run, 500 when signed in
- IPv6
- AAAA
- Readiness
By SimpleVerifier Team · Last updated
Also in: Português (Brasil) · Español · Deutsch · Français
Checking a whole portfolio, or the domains you send email from?
- Over 500 domains? Run them in batches of 500 when signed in and download the CSV after each.
- Sending mail over IPv6? Gmail requires a reverse DNS (PTR) record on the sending address; check it with the reverse DNS lookup.
- Mailing addresses on these domains? Check the list at /verify. The first 100 email checks are free with a Google sign-in, no card.
How do I check if a domain supports IPv6?
- Paste one domain, or a list one per line: up to 100 a run, or 500 after a free Google sign-in. Addresses and URLs are trimmed to the domain.
- Press Check IPv6. Each domain's A and AAAA records are looked up for the domain, www, up to three MX hosts and up to four name servers.
- Read the Website, Mail and DNS pills for each domain, and the reasons: which host names lack IPv6, and any AAAA that isn't a public address.
- Download the CSV with every IPv6 address found, to hand to whoever runs the hosting, mail or DNS.
Example
- You enter
- Two domains:
acme.exampleandglobex.example. - You get
acme.exampleIPv6 ready: the domain and www, both MX hosts and all four name servers have AAAA records.globex.examplePartly IPv6: Website No (no AAAA for the domain or www), Mail Yes, DNS Yes. Download the CSV with every IPv6 address found.- Limits
- Up to 100 domains a run without an account and 500 when signed in with Google. DNS only; addresses aren't connected to.
What makes a domain IPv6 ready?
An IPv6 address published in DNS for each service: an AAAA record (RFC 3596) for the website's host names, for each mail server named in MX, and for the domain's name servers. A visitor or mail server with only IPv6 can then reach all three. Most networks today are dual-stack and fall back to IPv4, so a missing AAAA rarely breaks anything, but IPv6-only networks, which some mobile carriers run, rely on translation when it's missing.
The checker reads those records for the domain and www, up to three MX hosts and four name servers. Website is Yes when both names have IPv6, Partly when one does; Mail is Yes when every MX host does; DNS is Yes when at least one name server does.
Does IPv6 matter for email?
For receiving, an MX host with an AAAA record lets IPv6-only senders deliver directly. For sending, it matters more: Google's sender guidelines require every sending IP, IPv4 or IPv6, to have a PTR (reverse DNS) record that resolves back to it, so a server that sends over IPv6 needs reverse DNS set up for its IPv6 address too.
Addresses that aren't public, such as ::1, link-local (fe80::/10), unique local (fc00::/7) or the documentation range 2001:db8::/32 (RFC 6890), can't be reached from the internet. The checker lists them separately and doesn't count them as IPv6.
Who uses this tool, and for what?
- IT teams
- Find which company domains, mail servers and DNS providers still lack IPv6.
- Agencies
- Show clients whether their hosting is IPv6 ready before a migration.
- Network engineers
- Audit a portfolio's AAAA coverage and catch records pointing at unreachable addresses.
- Cold emailers
- See whether a sending domain's mail servers accept IPv6 before turning on IPv6 sending.
What can’t this tool tell you?
- DNS only: it doesn't connect to the IPv6 addresses, so firewalls or broken routes don't show.
- It checks the domain and www only, up to three MX hosts and four name servers.
- It doesn't check reverse DNS for the IPv6 addresses; use the reverse DNS lookup for that.
- Up to 100 domains a run without an account and 500 signed in.
Common questions
- How do I know if my website supports IPv6?
- Look for an AAAA record on the website's host name. This checker looks up the domain and www, plus mail and name servers, and says which have IPv6 addresses.
- Does the checker connect over IPv6?
- No. It reads DNS only and doesn't connect to the addresses, so it can't tell you whether a firewall blocks IPv6 traffic. A published AAAA record is the first requirement.
- Why is my domain Partly IPv6?
- Some of its services have IPv6 addresses and others don't. Commonly the mail and DNS providers support IPv6 while the web host doesn't, or www has an AAAA record and the bare domain doesn't.
- Is IPv4 only a problem?
- Rarely today: almost every network can still reach IPv4. IPv6-only networks reach it through translation such as NAT64 and DNS64 (RFC 6146, RFC 6147).
- Can I check many domains at once?
- Yes. 100 domains a run without an account and 500 after a free Google sign-in, with a CSV of every address found.
- Is the IPv6 checker free?
- Yes, it's a free tool with no card. DNS lookups only.
Sources
You audited one domain. Cold outreach means thousands.
This tool checks a domain you type in. It will not tell you which addresses at that domain are real.
- Bulk mailbox verification with real SMTP checks
- The email finder — name plus company to a verified address
- Website enrichment for emails, owner names and socials
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.