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.
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 monitoring regions (US East Virginia, US West Oregon, Europe London, Asia Singapore).
- 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
- Direct probes from our monitoring infrastructure. We do not aggregate crowd reports, Twitter mentions, or DownDetector signals — every result on this page is a live network request.
Related
- TLS certificate checker — read the live cert for any host.
- Multi-region HTTP probe — check live status from US East / US West / EU / Asia.
- DNS propagation explained
- Flush DNS cache by OS