What do A, MX, CNAME, TXT, and NS records do?

A (and AAAA) map hostnames to IP addresses. MX tells mail servers where to deliver email for the domain. CNAME aliases one name to another. TXT carries arbitrary text—often SPF, DKIM, DMARC, or domain verification tokens. NS lists the authoritative nameservers that publish your zone.

Why do DNS changes take time to show up everywhere?

Resolvers cache answers according to each record’s TTL (time to live). Until TTLs expire, clients may see old data. Some providers also have slow secondary sync or anycast propagation. Lower TTLs before a planned change, then raise them after stabilization.

How does TTL affect troubleshooting?

A high TTL means longer stale-cache windows after a mistake or migration. A very low TTL increases query load but speeds rollback. For cutovers, many teams drop TTL to 300 seconds a day ahead, switch, verify, then restore a normal TTL.

My email bounces—what should I check in DNS?

Confirm MX points to the correct hosts, that those hosts resolve (A/AAAA), and that SPF (TXT), DKIM (TXT/CNAME depending on provider), and DMARC (TXT) align with your sending infrastructure. Misaligned SPF or missing MX are common causes; cross-check with an [email validator](/email-validator) after fixing records.

Why would I compare DNS to SSL or WHOIS data?

DNS tells you how traffic is routed; WHOIS shows registration and sometimes nameserver delegation at the registrar. TLS/SSL depends on the name clients use—CNAME chains and wrong A records often cause certificate name mismatches. Use our [SSL certificate checker](/ssl-certificate) and [domain WHOIS](/domain-whois) alongside DNS lookups.

DNS Lookup

v1.0.0

Run a fast DNS Lookup to view A, AAAA, CNAME, MX, TXT and NS records and troubleshoot domain propagation issues. See TTLs, record sources and full query output to diagnose email routing, CDN setup and DNS misconfigurations quickly.

DNS records will appear here

Query public DNS for A, MX, CNAME, TXT, NS, and more in seconds. Use it to verify deployments, debug mail, and confirm nameserver delegation without installing dig or juggling CLI flags.

Read the full guide →

Frequently Asked Questions

What do A, MX, CNAME, TXT, and NS records do?: A (and AAAA) map hostnames to IP addresses. MX tells mail servers where to deliver email for the domain. CNAME aliases one name to another. TXT carries arbitrary text—often SPF, DKIM, DMARC, or domain verification tokens. NS lists the authoritative nameservers that publish your zone.
Why do DNS changes take time to show up everywhere?: Resolvers cache answers according to each record’s TTL (time to live). Until TTLs expire, clients may see old data. Some providers also have slow secondary sync or anycast propagation. Lower TTLs before a planned change, then raise them after stabilization.
How does TTL affect troubleshooting?: A high TTL means longer stale-cache windows after a mistake or migration. A very low TTL increases query load but speeds rollback. For cutovers, many teams drop TTL to 300 seconds a day ahead, switch, verify, then restore a normal TTL.
My email bounces—what should I check in DNS?: Confirm MX points to the correct hosts, that those hosts resolve (A/AAAA), and that SPF (TXT), DKIM (TXT/CNAME depending on provider), and DMARC (TXT) align with your sending infrastructure. Misaligned SPF or missing MX are common causes; cross-check with an [email validator](/email-validator) after fixing records.
Why would I compare DNS to SSL or WHOIS data?: DNS tells you how traffic is routed; WHOIS shows registration and sometimes nameserver delegation at the registrar. TLS/SSL depends on the name clients use—CNAME chains and wrong A records often cause certificate name mismatches. Use our [SSL certificate checker](/ssl-certificate) and [domain WHOIS](/domain-whois) alongside DNS lookups.