dns DNS Lookup (A, MX, TXT, NS) star

How It Works

Enter a domain, choose a record type, and the lookup goes out over DNS-over-HTTPS (DoH) to Google's public resolver at 8.8.8.8 — a JSON-over-HTTPS API rather than the traditional binary UDP port-53 protocol. That's a deliberate choice: DoH runs over standard HTTPS, so it works from inside a browser without raw socket access, and — just as importantly — it bypasses whatever DNS resolver your operating system, router or ISP would normally use. Your own machine, your office network and your ISP each keep their own DNS cache, and each refreshes on its own schedule based on the record's TTL (Time To Live), so at any given moment they can each show a slightly different, slightly stale answer. Querying Google's resolver directly sidesteps all three of those caches and shows what a large, frequently-refreshed public resolver currently believes — the closest available proxy for "what the internet sees right now," though still one resolver's view, not a global guarantee.

Each record type answers a different operational question. A and AAAA records map a hostname to an IPv4 or IPv6 address — this is what your browser resolves before it can even open a connection. MX records list which mail servers accept email for the domain, each with a numeric priority (lower number = tried first) — useful when migrating email providers, since a stale MX record means mail keeps routing to the old provider. TXT records are unstructured, arbitrary text and are where SPF, DKIM and domain-verification strings live; a domain can have several, and a malformed or missing SPF TXT record is one of the most common reasons legitimate email lands in spam. CNAME records point one hostname to another as an alias (www pointing to the bare domain, or a subdomain pointing to a CDN endpoint) — a hostname with a CNAME cannot also carry other record types at the same name, a common source of "why won't this subdomain also have an MX record" confusion. NS records list the authoritative name servers responsible for answering queries about the domain at all — if these are wrong or out of sync with the registrar, no other record for the domain resolves correctly anywhere.

A typical use: after moving a website to a new host, you point the A record at the new server's IP. Propagation isn't instant — it's bounded by the old record's TTL, so a record set to TTL 3600 (one hour) can take up to an hour to disappear from caches worldwide, and some resolvers ignore TTL and cache longer than they should. Querying Google's DoH resolver directly lets you check "has the new value reached at least this one major resolver" without waiting for your own ISP's cache to expire.

What to Know

• Because DNS-over-HTTPS bypasses local caches, results here can be more current than what nslookup or your OS reports — that's expected, not a bug.
• A, MX, TXT, CNAME and NS cover virtually all propagation, mail and verification checks; rarer types like SRV or CAA aren't currently included.
• DNS changes are cached, not instant — expect a delay bounded by the previous TTL, not immediate global effect.