A and AAAA
Confirm the domain points to the expected IPv4 and IPv6 addresses before changing web or CDN routing.
DNS diagnostics
DNS Lookup Online
Use this online DNS lookup tool to check A, AAAA, CNAME, MX, NS, TXT, and SOA records for a domain, or enter an IPv4 address for an IP-to-DNS reverse lookup.
DoH lookupUses DNS-over-HTTPS for reliable browser-based queries.
Record filtersShow only the DNS record family you need.
TTL visibilitySee cache timing beside each returned answer.
Run a domain or reverse DNS lookup
Choose a record type, enter a domain or IPv4 address, and review the grouped answers below.
Start a DNS lookup
Enter a domain above and click Search to see DNS records here.
What to check in DNS results
MX and TXT
Mail problems often come from missing MX records or incorrect SPF, DKIM, and DMARC TXT values.
NS and SOA
Nameserver and SOA records help identify who is authoritative and whether zone metadata looks current.
IP geolocation lookup
After checking A or AAAA records, use the IP geolocation lookup to review approximate location, ASN, and organization details.
DNS Troubleshooting Workflow
Start with the record type that matches the symptom. If a website is not loading, check A, AAAA, and CNAME records. If email is failing, check MX records and TXT records for SPF, DKIM, and DMARC. If new records are not appearing, compare TTL values and nameserver records to confirm whether the authoritative zone has changed or a resolver is still using cached data.
DNS issues often look like application problems. A browser error, mail bounce, failed certificate validation, or CDN misroute may begin with a missing record, an old CNAME, an incorrect MX priority, or a TXT record copied with extra spaces. Use the lookup result with device tests such as nslookup, dig, ping, and traceroute to separate name resolution from network reachability.
When changing records, note the old value, the new value, and the TTL before the change. Lowering TTL in advance can make planned migrations smoother, while checking NS and SOA records helps confirm that you are editing the correct authoritative DNS zone.
If a result looks wrong, test from more than one resolver and compare with the authoritative nameserver. Public resolvers can cache older answers, while an authoritative query shows what the zone currently publishes. This is especially useful during website moves, mail migrations, CDN onboarding, and certificate validation checks.
How DNS lookup works step by step
This DNS lookup process diagram is a simplified visual of a normal recursive query. Cached answers can allow the process to finish before every step is needed.
1. Client request
Your browser, application, or command-line DNS lookup asks for a record such as an A, AAAA, MX, or TXT record.
2. Recursive resolver
The configured resolver checks its cache. This page performs a Google DNS lookup through Google's DNS-over-HTTPS endpoint.
3. Root and TLD referral
Without a cached answer, the resolver follows referrals from a root server to the appropriate top-level-domain nameserver.
4. Authoritative answer
The authoritative nameserver returns the requested record or a response explaining that the name or record does not exist.
5. Response and cache
The resolver returns the answer to the client and may cache it for the record's TTL to make later lookups faster.
DNS Lookup Frequently Asked Questions
What is DNS lookup?
A DNS lookup asks the Domain Name System for records associated with a name or address, such as website IP addresses, mail servers, nameservers, text policies, or a reverse hostname.
What is reverse DNS lookup?
A reverse DNS lookup converts an IP address into its reverse lookup name and requests a PTR record. Enter an IPv4 address above to run an IP-to-DNS lookup and see the hostname published by the address owner.
How do you do a DNS lookup from CMD or a terminal?
On Windows, run nslookup example.com. With dig installed, run dig example.com A. For reverse lookup, use nslookup 8.8.8.8 or dig -x 8.8.8.8.
What is forward and reverse lookup in DNS?
Forward lookup maps a hostname to records such as A or AAAA addresses. Reverse lookup maps an IP address to a PTR hostname under the reverse DNS namespace.
What are forward and reverse lookup zones?
A DNS forward lookup zone stores name-to-data records such as A and AAAA. A reverse lookup zone stores PTR records used to map IP addresses back to hostnames.
How do you fix a DNS lookup failure?
Verify the name and record type, test another resolver, inspect authoritative NS and SOA records, clear or bypass local caches, and determine whether the response is a missing record, timeout, delegation error, or DNSSEC failure.
How do you fix a slow DNS lookup?
Compare resolvers, test the authoritative nameserver, check for packet loss and DNSSEC delays, review search-suffix configuration, and inspect whether repeated queries are missing cache because of a very low TTL.
Is WHOIS lookup the same as DNS lookup?
No. DNS lookup returns active name-service records, while WHOIS or RDAP lookup provides registration, allocation, and ownership information.
Does this tool provide bulk DNS lookup or DNS lookup history?
No. This page performs a current lookup for one domain or IPv4 address at a time. It does not maintain historical DNS datasets or submit a bulk list.
How do you disable DNS lookup on a Cisco router or switch?
In Cisco IOS global configuration mode, no ip domain lookup disables automatic name resolution for mistyped commands. This device setting is separate from querying public DNS records with this page.