DNS & Network Tools
Free tools to inspect DNS records, check propagation, scan ports, geolocate IPs, troubleshoot HTTP, SSL, SMTP, and FTP errors, and explore TLD data. No signup required.
DNS Tools
Inspect, verify, and troubleshoot DNS records and propagation for any domain.
DNS Inspector
Look up A, AAAA, MX, NS, TXT, CNAME, SOA, and CAA records for any domain. Full DNS record analysis with DNSSEC validation status.
Open ToolDNS Propagation Checker
Check how DNS changes are propagating across global servers in real-time. Monitor nameserver updates, TTL countdown, and resolution consistency worldwide.
Open ToolReverse Nameserver Lookup
Find every domain delegated to a specific nameserver. Reveal hosting concentration, white-label DNS providers, and customer footprints across millions of indexed zones.
Open ToolWHOIS & Domain Tools
Look up domain ownership, registration history, expiry dates, and browse expiring domains.
WHOIS Lookup
Look up domain registration details — registrar, nameservers, creation and expiry dates, and domain status codes from WHOIS/RDAP data.
Open ToolDomain Age Checker
Check when a domain was first registered and calculate its exact age. Useful for SEO analysis, trust assessment, and domain valuation.
Open ToolDomain Expiry Checker
Check when a domain expires and whether auto-renew is enabled. Monitor expiry dates to avoid accidental domain loss.
Open ToolReverse WHOIS
Find all domains registered by an owner, registrar, or nameserver. Discover domain portfolios and brand assets.
Open ToolBulk WHOIS
Look up WHOIS data for multiple domains at once. Export results as CSV for portfolio management and competitive analysis.
Open ToolExpiring Domains
Browse domains expiring soon across all TLDs. Filter by TLD, age, and length to find valuable dropping domains.
Open ToolDomain Marketplace
Search 20M+ domains for sale across major aftermarket platforms. Compare prices and find your perfect domain.
Open ToolWeb Inspection
Audit on-page SEO, inspect HTTP responses, trace redirect chains, check robots.txt files, and analyze TLS certificates.
On-Page SEO Auditor
Comprehensive on-page SEO audit analyzing 70+ ranking factors — meta tags, headings, structured data, keyword density, image optimization, link validation, robots.txt access, and AI search readiness.
Open ToolPage Speed Test
Measure Core Web Vitals (LCP, INP, CLS) and full PageSpeed Insights metrics for any URL on mobile and desktop. Identifies bottlenecks with prioritized fixes ranked by Lighthouse impact.
Open ToolRobots.txt Checker
Fetch and validate any site's robots.txt file. Check for correct content-type, detect HTML responses, and parse User-agent blocks, Disallow/Allow rules, and Sitemap directives.
Open ToolHTTP Header Checker
Inspect any URL with a full timing waterfall — DNS lookup, TCP connect, TLS handshake, and time to first byte. View TLS certificate details, request/response headers, and body metadata.
Open ToolRedirect Checker
Trace HTTP redirect chains hop by hop in real-time. Detect redirect loops, view status codes and timing per hop, and see the final destination URL. Supports 301, 302, 303, 307, and 308 redirects.
Open ToolEmail Tools
Test email deliverability, validate authentication records, and diagnose mail server issues.
Email Tester
Test your email setup with a spam score from 0 to 10. Checks SPF, DKIM, DMARC, reverse DNS, and more to ensure inbox delivery.
Open ToolMX Lookup
Find mail exchange servers for any domain with priority, PTR records, and provider detection.
Open ToolSPF Record Checker
Validate SPF records with DNS lookup count, mechanism analysis, and actionable fix suggestions for authentication failures.
Open ToolDKIM Record Checker
Verify DKIM signatures, check key strength, and validate DNS records for email authentication.
Open ToolDMARC Record Checker
Analyze DMARC policy configuration, reporting addresses, and alignment settings for your domain.
Open ToolSMTP Diagnostics
Test mail server connectivity, TLS support, and SMTP response codes with a live connection test.
Open ToolEmail Header Analyzer
Trace the delivery path of any email — see hops, delays, authentication results, and security analysis.
Open ToolNetwork & Security
Scan ports, geolocate IPs, detect threats, and diagnose server and protocol errors.
IP Intelligence API
Real-time IP risk scoring API for fraud defense — VPN, proxy, Tor, datacenter, and residential-proxy detection in one call. Sub-100ms p50 from US edges. 1,000 free lookups per day, no credit card.
Open ToolReverse IP Domain Check
Find every domain hosted on a specific IP address. Reveal shared hosting neighbors, identify reseller infrastructure, and audit domain footprints across millions of indexed records.
Open ToolOpen Port Scanner
Scan TCP and UDP ports on any IP or domain. Audit cloud infrastructure, find exposed services, check firewall rules, and map your attack surface from outside your network.
Open ToolIP Geolocation Lookup
Find the physical location, ISP, ASN, and organization for any IP address. Includes threat intelligence — detect VPNs, proxies, Tor exit nodes, and cloud hosting.
Open ToolWhat's My IP Address
Detect your public IP address instantly. See your geolocation, ISP, and security assessment including VPN/proxy detection and threat reputation.
Open ToolBlacklist Checker
Check if a domain or IP address is listed on email and spam blacklists (DNSBLs). Scan 50+ blacklists in real-time to diagnose email deliverability issues and reputation problems.
Open ToolWebsite Reputation Checker
Check if any URL, domain, or IP is flagged for malware, phishing, or spam across 17 security vendors — Google Safe Browsing, threat intelligence feeds, and DNS blocklists. Get remediation guidance for flagged sites.
Open ToolHTTP Security Headers
Analyze security headers for any website and get a grade from A+ to F. Generate production-ready configs for Nginx, Apache, Cloudflare, Caddy, Vercel, and Next.js.
Open ToolCloudflare Error Diagnostics
Diagnose and fix Cloudflare 5xx origin errors and 1xxx Cloudflare-layer errors. Step-by-step troubleshooting with causes ranked by likelihood and CLI commands.
Open ToolHTTP Status Codes
Complete reference of HTTP status codes from 1xx to 5xx. Understand what each code means, when it occurs, common causes, and step-by-step fixes.
Open ToolSSL/TLS Error Reference
Diagnose SSL certificate errors, TLS handshake failures, and OpenSSL errors. Troubleshooting guides with openssl commands and certificate chain analysis.
Open ToolSMTP Error Codes
Troubleshoot email delivery failures with SMTP error code reference. Covers 2xx-5xx responses with DNS record checks, authentication fixes, and relay diagnostics.
Open ToolFTP Error Codes
Diagnose FTP file transfer errors with complete reply code reference. Covers 1xx-5xx responses with active vs passive mode fixes, firewall diagnostics, and authentication troubleshooting.
Open ToolDeveloper Utilities
Converters and references for common developer tasks — timestamps, encoding, and more.
Reference
Server administration references and guides.
Domain Data & Reports
Live data on TLD registries, DNS providers, domain companies, marketplaces, and security findings — updated daily from zone file analysis.
TLD Directory
Browse 1,900+ top-level domains with registry details, DNSSEC status, DNS provider breakdown, and registration pricing.
Open ToolDomain Rankings
Live rankings of TLDs by domain count, DNS providers by market share, and DNSSEC adoption rates. Updated daily.
Open ToolDomain Availability
Registration density for 1-12 character domain names across TLDs. See where short domains are still available.
Open ToolDNS Provider Directory
DNS hosting providers ranked by market share with TLD breakdown, parent company details, and infrastructure data.
Open ToolDomain Company Directory
Registry operators and DNS holding companies with brand portfolios and consolidated market share data.
Open ToolDomain Marketplace Inventory
Aftermarket platforms with domain inventory counts, TLD breakdown, and parent company information.
Open ToolDNS Security Dashboard
Security findings from daily analysis — typosquatted nameservers, lame delegations, provider concentration risks, and DNSSEC gaps.
Open ToolDeveloper APIs
Programmatic access to every tool on this site. Build domain-monitoring, fraud-defense, and email-deliverability features into your own apps.
API Documentation
Full REST reference for the public API. Auth, rate limits, response shapes, and copy-paste examples in cURL, JavaScript, Python, PHP, Ruby, and Java for 21 endpoints across DNS, WHOIS, IP intelligence, email, security, and SEO.
Open ToolIP Intelligence API
Real-time IP reputation API with VPN, proxy, Tor, and datacenter detection. Powers the IP Geolocation tool above. Sub-100ms p50, 1,000 free lookups per day, dedicated tiers from $49 to $499 per month.
Open Tool