DNS Lookup

What this tool checks

A and AAAA records point names to IP addresses, MX records identify mail servers, TXT records often contain verification or email-policy text, CNAME records alias one hostname to another, NS records list authoritative name servers and CAA records can restrict certificate authorities.

How to read a result

Suppose you look up an A record for example.com. If the resolver returns one or more IPv4 addresses, those are the public answers Cloudflare had for that query at that moment. For MX records, a result usually includes a priority number and a mail-host name; lower priority numbers are generally tried first by sending mail systems.

The TTL value is a cache lifetime expressed in seconds. A TTL of 300 means a resolver may keep that answer for about five minutes before asking again. It does not mean a DNS change will become visible everywhere at exactly that time because different resolvers, negative caching and previously cached answers can produce different transition times.

Useful troubleshooting workflow

When a DNS change appears wrong, first check the exact record type you changed, then compare the result with the DNS provider's control panel. If the answer is still old, wait for the prior TTL to expire and test again. For mail issues, inspect MX plus relevant TXT records such as SPF or verification entries instead of checking only the website's A record.

Source, privacy and limitations

The browser sends the domain name and selected record type directly to Cloudflare’s 1.1.1.1 DNS-over-HTTPS JSON endpoint. NexusNova does not add a backend proxy for this tool. DNS results are public infrastructure data and may change as DNS caches expire.

This page reports the resolver answer; it does not independently validate DNSSEC, prove ownership of a domain, test every recursive resolver worldwide or guarantee that an email or website service behind the record is healthy. For authoritative troubleshooting, compare with your DNS host and command-line tools such as dig or nslookup.

Check the served TLS certificate · Test browser reachability · Calculate an IPv4 subnet

What a DNS lookup can prove

DNS records help clients locate services. A records can map a name to IPv4, AAAA to IPv6, MX records describe mail routing, TXT records carry text-based configuration, and CNAME records provide aliases. The returned set is one view of the domain's current public DNS state.

Caching means a resolver can serve an earlier answer until its TTL expires. A changed record may therefore appear differently across networks for a while without either resolver being broken.

Use DNS as one diagnostic signal

Compare the returned data with the authoritative provider configuration and the service you expect. Correct DNS does not itself prove application availability, certificate validity, routing or firewall access.

Use DNS records to troubleshoot the right layer

DNS lookup asks a resolver for public records. A maps a name to IPv4; AAAA to IPv6; MX routes mail; TXT can hold verification or email-authentication values; CNAME aliases a name; NS identifies name servers; and CAA can restrict certificate authorities.

A practical troubleshooting sequence

1. Enter the hostname or domain without a copied URL path.
2. Choose the record type related to the issue, such as MX for mail routing or A/AAAA for address resolution.
3. Review the answer, TTL and any alias chain shown by the resolver.
4. Compare the response with the domain owner's intended DNS configuration before changing records.

If a record was changed recently, cached answers may remain visible until their TTL expires. A successful answer from one recursive resolver does not mean every resolver worldwide has updated, and a missing record does not by itself prove that a website is down. Check authoritative name servers and the service configuration when the problem affects a production domain.

Privacy and limits

This lookup uses a public DNS-over-HTTPS resolver. The resolver sees the query, so avoid submitting internal hostnames or confidential infrastructure names unless you are authorised to do so. Public DNS records are only one part of troubleshooting; they do not prove that the target server is listening, that TLS is configured correctly or that an email will avoid spam filtering.

DNS lookup questions

Why do two DNS tools return different answers?

They may query different recursive resolvers, use different caches or follow alias chains differently.

Does a DNS result confirm a website is online?

No. DNS resolution and service reachability are separate checks.