DNS & domains

DNS lookup

See the DNS records of any domain – addresses, mail servers, name servers, TXT records and more.

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DNS record types explained

A / AAAA – the IPv4 / IPv6 address of a name. This is where a website lives.
CNAME – an alias that points one name at another name.
MX – the mail servers that receive email for a domain, in order of priority (lower number first).
NS – the name servers responsible for the domain.
TXT – free text, used for SPF, DKIM, DMARC and domain verification.
SOA – technical details about the zone, including its serial number.
CAA – which certificate authorities may issue SSL certificates for the domain.
SRV – the host and port of a specific service (enter a name like _sip._tls.example.com).
PTR – the hostname of an IP address (enter an IP to look it up).

Why do I see different results from different DNS servers?

DNS answers are cached for the time shown as TTL (time to live). After you change a record, servers keep the old answer until it expires – this is "DNS propagation". Comparing Cloudflare, Google and Quad9 shows whether a change has spread.

Everyday tasks with DNS lookup

Check that a new website points to the right server

After changing hosting, look up the A (IPv4) and AAAA (IPv6) records for both example.com and www.example.com. They should match the IP addresses your new host gave you. If the www name is a CNAME, follow it to the final address.

Troubleshoot email delivery

MX records must point to your mail provider’s servers (for example Google Workspace or Microsoft 365). The lowest priority number is tried first.
TXT records should contain exactly one SPF record starting with v=spf1. Two separate SPF records is a common mistake that makes both invalid.
Look up _dmarc.example.com (TXT) to check your DMARC policy, and selector._domainkey.example.com for a DKIM key.

Verify domain ownership

Services like Google Search Console, Microsoft 365 and certificate authorities ask you to add a TXT record. Use this tool to confirm it is published before clicking “verify”.

Check which certificate authorities may issue certificates

A CAA record lists the authorities allowed to issue SSL certificates for your domain, such as 0 issue "letsencrypt.org". If certificate renewal fails, an outdated CAA record is a frequent cause.

Planning a DNS change

Because resolvers cache answers for the record’s TTL, lower the TTL to 300 seconds (five minutes) a day before a planned move, make the change, check it here against all three resolvers, and raise the TTL again once everything works.

Reading the answer

If the tool returns NXDOMAIN, the name does not exist at all – check the spelling or whether the domain has expired (use WHOIS). No records means the name exists but has no record of the type you asked for. SERVFAIL usually indicates a problem with the domain’s name servers or a DNSSEC error.

For a complete explanation of every record type, see DNS records explained.

DNS lookup – frequently asked questions

How long does DNS propagation take?

“Propagation” is really cache expiry. Most changes are visible within minutes to a few hours, depending on the old TTL. Changing name servers at the registrar can take up to 24–48 hours.

Can I put a CNAME on my root domain?

Not in standard DNS – a CNAME cannot coexist with the SOA and NS records at the root. Many DNS providers offer “CNAME flattening” or ALIAS records to achieve the same thing.

Why is my site working for me but not others?

Your computer or router may have cached the new record while other resolvers still hold the old one, or the other way round. Compare resolvers in this tool, and flush your local cache with ipconfig /flushdns on Windows.