DNS

DNS record checker

Resolve A, AAAA, CNAME, MX, NS, TXT, and SOA records for any public hostname in parallel. Surfaces missing IPv6, missing SPF, and other operational signals you'd otherwise have to dig out of dig +short.

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Methodology

Probe
We resolve A, AAAA, CNAME, MX, NS, TXT, and SOA records in parallel via Node's built-in dns.promises against the system resolver. Every query has a 5-second timeout; non-existent record types are reported as no records rather than errors.
Counts as DOWN
All address-resolution attempts fail. The most informative form is NXDOMAIN (the authoritative server explicitly says "no such name"); other forms are server errors or timeouts.
Counts as DEGRADED
Reserved for partial responses, some record types resolved, others timed out. Usually a flaky upstream or rate-limited authoritative server.
Detail
We surface the records as the resolver returned them, plus operational warnings: missing AAAA (IPv4-only), missing MX (cannot receive mail at the apex), missing SPF in TXT (outbound mail likely flagged as unauthenticated). We do not enumerate zone files, attempt zone transfers (AXFR), or run DNSSEC validation.
Cadence
Every 5 minutes, in parallel across 4 independent probe methods (HTTP/1.1 with strict TLS, HTTP/2, a browser User-Agent GET, and a curl-style HEAD) from our edge network. We check probe diversity, not geography — if a site blocks a non-browser User-Agent or only speaks HTTP/1.1, the four cards show it.
Rate-limited targets
If a host returns 429 or consistently drops connections from our IPs, we cap retries at 3 and report the last observed status, we do not flood the target to confirm the outage.
Data source
Our verdict is based on direct multi-method probes, every result above is a live network request, never a Twitter mention or DownDetector aggregate. User reports, when shown, appear separately below as a supplementary signal and are never used to determine the up/down verdict.

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