Nslookup

Look up all common DNS records (A, AAAA, NS, MX, TXT, CNAME, SOA) for a domain. Returns results from a specified DNS server.

Look up a specific DNS record type for a domain. Supports 53 record types including A, AAAA, MX, TXT, CNAME, SOA, PTR, CAA, SRV, DNSKEY, DS, TLSA, HTTPS, SPF, and more.

Check DNS propagation for a domain across 18+ global DNS servers (Cloudflare, Google, Quad9, OpenDNS, regional servers, and authoritative nameservers). Shows if DNS changes have propagated worldwide.

Get the IP addresses (both IPv4 and IPv6) for a domain by looking up A and AAAA records. Also returns the punycode and unicode domain representations.

Check the SSL/TLS certificate for a domain. Returns issuer, expiry date, days until expiry, certificate chain validity, cipher strength, SAN domains, fingerprint, and TLS protocol version.

Check BIMI (Brand Indicators for Message Identification) and VMC (Verified Mark Certificate) for a domain. Returns BIMI DNS record status, VMC certificate details, logo URL, trademark info, and expiry.

Run a security scan on a domain to detect DNS misconfigurations, missing SPF/DKIM/DMARC records, cookie security issues, and other web security vulnerabilities. Returns findings with severity levels (critical, high, medium, low, info).

Perform a one-time HTTP uptime check on a URL from a single location. Returns whether the site is up or down, HTTP status code, and response time in milliseconds. For multi-location checks, use uptime_check_multi instead.

Check if a website is up or down from 7 global locations simultaneously: Amsterdam, Sydney, London, Frankfurt, Delhi, Warsaw, and South Carolina. Returns status, response time, and HTTP status code for each location.

Run a comprehensive DNS health audit on a domain — 39 checks across 7 categories: DNSSEC (chain of trust, algorithms, validation), MX & email (PTR, MTA-STS, redundancy), DNS hygiene (SPF conflicts, wildcards, apex CNAME), TTL & SOA configuration, nameserver setup (diversity, lame delegation, EDNS0),

Check a domain's GEO (Generative Engine Optimization) score — how well the site is optimized for AI search engines like ChatGPT, Gemini, Claude, and Perplexity. Returns three scores (Technical Readiness, Entity Readiness, Answer Readiness), AI crawler access status, structured data analysis, and pri

Look up registration data (RDAP — the successor to WHOIS) for an IP address, AS number, or domain name. The query type is detected automatically. Returns the owning organization, network range/CIDR, RIR (ARIN, RIPE, APNIC, LACNIC, AFRINIC), country, status, registration/last-changed dates, nameserve

Find out who hosts a website. Returns the hosting provider, IP/ASN/network owner, server location, DNS/nameserver provider, CDN or proxy detection (Cloudflare, Fastly, etc.), SSL certificate issuer, and mail servers/provider for a domain in one combined report.

Scan a domain's email security posture: SPF, DKIM, DMARC, and BIMI configuration. Returns per-indicator scores and detected issues so you can see how well the domain is protected against spoofing and phishing.

Review proposed DNS changes BEFORE applying them. Compares a domain's current public DNS with a proposed future state, returns a diff, deterministic rule-based findings (SPF/DMARC/MX/CAA/DNSSEC pitfalls, dangling records, mail breakage, etc.) with suggested fixes, and an overall 0-100 risk score. St

Check only the BIMI (Brand Indicators for Message Identification) DNS record for a domain — faster than bimi_vmc because it skips the VMC certificate download and validation. Returns the BIMI record at default._bimi.<domain>, logo URL, and authority (VMC) URL if declared.

Read a public status page hosted on nslookup.io status pages. Returns the page name, overall status, per-component status and uptime, and active incidents/maintenance. Look up by slug (pages served at hosted.nslookup.io/<slug>) or by the custom domain the page is served on. Provide exactly one of sl

Get an account health snapshot for your NsLookup.io monitoring: an aggregated 0-100 health score with per-subsystem breakdown (uptime, SSL, DNS, propagation, VMC, WHOIS) plus your current product limits/quota. Requires sign-in to your NsLookup.io account (or an API token).

List all monitors in your NsLookup.io account across every type — uptime, API, DNS, WHOIS, DNS propagation, SSL certificates, and BIMI/VMC — with their configuration and latest known state. Requires sign-in to your NsLookup.io account (or an API token).

List incidents from your NsLookup.io monitoring (downtime, SSL expiry, DNS changes, propagation issues, VMC problems) — open ones by default, or the full recent history — plus a per-status/per-source summary. Requires sign-in to your NsLookup.io account (or an API token).

Get uptime and response-time history for one of your NsLookup.io uptime monitors: availability stats plus hourly buckets over the requested window. Identify the monitor by id or by URL. Requires sign-in to your NsLookup.io account (or an API token).

List recent DNS changes detected on your monitored domains, each with its DNS Change Review risk assessment (0-100 risk score, severity counts, added/removed/modified record counts), plus the latest risk per monitor. Requires sign-in to your NsLookup.io account (or an API token).

Get an SSL certificate expiry overview for your monitored domains: per-alert-level counts (ok / warning / critical / expired) and every certificate sorted by soonest expiry, highlighting the ones expiring within 30 days. Requires sign-in to your NsLookup.io account (or an API token).