80+ free tools for DNS lookup, SPF/DKIM/DMARC validation, SSL inspection, redirect analysis and more — powered by live global resolvers.
Type any domain name or IP address into the tool of your choice — no setup required.
We query Cloudflare, Google and Quad9 via DNS-over-HTTPS — fresh data every time, never cached results.
Get clear, actionable output with RFC references, TTL values, and specific recommendations — not raw data dumps.
Professional-grade internet diagnostic tools, free and always available.
DNS lookup, propagation checker, A/AAAA/MX/NS/TXT/CNAME/SOA/CAA records, DNSSEC validation and zone file analysis.
16 tools →SPF, DKIM, DMARC, BIMI, MTA-STS and TLS-RPT checkers. Email header analyzer and full deliverability audit.
11 tools →SSL certificate inspection, security headers grader, HSTS, CSP analyzer, cookie security and mixed content checker.
9 tools →WHOIS/RDAP lookup, domain age, reverse IP, geolocation, IP reputation, blacklist check and subdomain finder.
12 tools →Redirect chain tracer, HTTP status checker, robots.txt tester, sitemap validator, canonical and Open Graph checker.
9 tools →Generate SPF, DMARC, DKIM, CAA, robots.txt, .htaccess redirects, security headers, CSP and DNS zone files.
14 tools →Every DNS query uses DNS-over-HTTPS to Cloudflare (1.1.1.1), Google (8.8.8.8), and Quad9 (9.9.9.9) simultaneously. Results include the TTL, authoritative source, and provider attribution so you know exactly where the data came from.
Unlike tools that serve cached results of unknown age, nslookup.net queries live resolvers on every request.
Misconfigured SPF, DKIM, and DMARC records are the leading cause of email landing in spam. Our email security tools validate your records against the relevant RFCs and explain precisely what is wrong and how to fix it.
Use the Mail Deliverability Checker to audit every authentication record for a domain in a single pass.
Results include TTL values, RFC references, provider attribution, and specific recommendations — not raw data you have to interpret yourself. Every tool works without an account, without ads, and without rate-limit paywalls.
All 80+ tools are free to use. A public API for programmatic access is on the roadmap.
nslookup.net is a free collection of 80+ professional internet diagnostic tools covering DNS lookups, email authentication (SPF, DKIM, DMARC), SSL/TLS certificate inspection, HTTP security headers, redirect analysis, and web security. All tools are browser-based, require no account or registration, and return live results by querying real DNS resolvers and servers on every request.
Yes — all tools on nslookup.net are completely free with no hidden paywalls, rate-limit tiers, or account requirements. There are no ads and no upsells. The site is built for developers and IT professionals who need accurate tools they can rely on without friction.
DNS lookups are performed in real-time using DNS-over-HTTPS (DoH) to three independent public resolvers — Cloudflare (1.1.1.1), Google (8.8.8.8), and Quad9 (9.9.9.9). Results reflect live resolver data at the moment of your query. Because resolvers cache DNS records for the duration of each record's TTL, results include the TTL value so you know how fresh the data is.
A DNS lookup queries one or more resolvers from a single location to retrieve current DNS records. A DNS propagation checker queries resolvers in multiple geographic locations simultaneously, letting you see whether a recent DNS change has propagated worldwide or is still returning old values in some regions. Use the lookup for checking current records; use the propagation checker after making DNS changes to monitor global rollout.