A/AAAA lookup
See which IP addresses a domain points to, both IPv4 (A) and IPv6 (AAAA).
About A/AAAA lookup
What it is
The A record (Address) in DNS points a domain to an IPv4 address. The AAAA record does the same for IPv6. These are the records that let a browser find the right server when someone types in your address.
Why it matters
If the A record points to the wrong place, visitors and systems end up on the wrong server. If it does not match the PTR record (reverse DNS), it can also affect mail delivery and reputation.
Tips
- Check that the A record points to your actual server's IP, not an old one.
- IPv6 (AAAA) is not mandatory but increasingly common, set it up if your provider supports it.
- The TTL value controls how quickly a change takes effect, keep it reasonable (3600s is common).
Common questions
What is the difference between A and AAAA?
A points to an IPv4 address (e.g. 93.184.216.34) and AAAA to an IPv6 address. Both do essentially the same thing, but for different network protocols.
Do you have to have an AAAA record?
No, it is not a requirement but it is good practice. IPv6 is used increasingly and makes your site reachable from more networks.
More lookups
MX lookup
See which servers receive mail for a domain, and which provider handles it.
SPF check
Check whether a domain has an SPF record and how strictly it rejects spoofed mail.
DMARC check
See whether a domain has DMARC and which policy it uses against spoofed mail.
DKIM check
Look for DKIM signing on a domain using the most common selectors.
DNSSEC check
See whether a domain is protected with DNSSEC, that is, whether its DNS answers are signed.
TXT lookup
List all TXT records for a domain, including SPF, verifications and more.
NS lookup
See which name servers control a domain's DNS.
Blacklist check
Check whether a domain's IP address is on blacklists such as Spamhaus, Barracuda and SpamCop.
CNAME lookup
See whether a domain is an alias that points on to another domain.
SOA lookup
See the zone's core data: primary name server, contact and serial number.
CAA lookup
See which certificate authorities are allowed to issue certificates for the domain.
Reverse DNS (PTR)
Look up which host name a domain's IP address points back to.
MTA-STS
See whether a domain requires encrypted mail delivery via MTA-STS.
TLS-RPT
See whether a domain receives reports about failed encrypted mail delivery.
BIMI
See whether a domain publishes a logo that can be shown in the recipient's inbox.
SSL certificate
Check a domain's TLS certificate: issuer, validity and expiry.
Whois
See who owns a domain, when it was registered and when it expires.
HTTP security headers
Check whether a domain's website sets important security headers.