Complete catalogue of DNS query, security, performance, mail and network diagnostic tools.
| Tool | Description | |
|---|---|---|
| DNS Lookup | Query A, AAAA, MX, NS, TXT, SPF, DMARC, DKIM, SOA, SRV and PTR records for any public domain. | Open |
| MX Lookup | List MX hosts and priorities so you can see where a domain receives mail. | Open |
| CNAME Lookup | Resolve CNAME records on the apex and www host. | Open |
| NS Lookup | Show nameservers and the IPv4/IPv6 addresses glued to them. | Open |
| TXT Lookup | Read TXT records used for SPF, domain verification and custom policies. | Open |
| AAAA Lookup | Check whether a domain publishes IPv6 AAAA records. | Open |
| Reverse DNS | Resolve the PTR hostname attached to a public IPv4 or IPv6 address. | Open |
| Bulk DNS Lookup | Query A, MX and NS records for a short allow-listed batch of domains. | Open |
| Subdomain Finder | Check a fixed list of common subdomains. This is not an open-ended brute-force enumerator. | Open |
| DNS Compare | Compare A, AAAA, MX, NS, TXT, SPF and DMARC between two public domains. | Open |
| Tool | Description | |
|---|---|---|
| DNSSEC Validator | Check whether DNSSEC material is published for a domain. | Open |
| DNS Leak Test | Shows the public address this site received and its PTR. A true browser leak test needs a client-side resolver. | Open |
| Zone Transfer Test | Tests whether nameservers accept TCP/53. Zone contents are never returned. | Open |
| SPF Checker | Read and display the SPF TXT policy of a domain. | Open |
| DMARC Checker | Inspect the DMARC record published at _dmarc.example.com. | Open |
| DKIM Checker | Look up selector._domainkey TXT records used for DKIM. | Open |
| BIMI Checker | Read default._bimi TXT, require an HTTPS SVG location and optionally probe the logo URL. | Open |
| MTA-STS Checker | Inspect _mta-sts TXT and fetch https://mta-sts.example.com/.well-known/mta-sts.txt. | Open |
| TLS-RPT Checker | Read the _smtp._tls TXT record used for SMTP TLS reporting (TLS-RPT). | Open |
| Tool | Description | |
|---|---|---|
| DNS Cache Check | Show TTL values and SOA timers that control how long resolvers cache answers. | Open |
| DNS Response Time | Measure how long this server takes to resolve A records. | Open |
| DNS Speed Test | Compare Cloudflare, Google, Quad9 and OpenDNS over DNS-over-HTTPS. | Open |
| DNS Propagation | Ask several public resolvers for the same A record and compare answers. | Open |
| Tool | Description | |
|---|---|---|
| DNS Generator | Build A, AAAA, MX, NS, TXT, SPF, DKIM and DMARC records and export BIND or CSV. | Open |
| DMARC Generator | Create a DMARC TXT value with policy and optional rua mailbox. | Open |
| DKIM Generator | Format a DKIM public key as a selector._domainkey TXT record. | Open |
| BIMI Generator | Build a default._bimi TXT record from an HTTPS logo URL and optional VMC certificate URL. | Open |
| Tool | Description | |
|---|---|---|
| Domain Analysis | Combine DNS health, registration dates and IPv4 blacklist status into one score. | Open |
| Domain Age | Read the WHOIS creation date and compute domain age. | Open |
| Domain Expiry | Show registrar expiry date and remaining days from WHOIS. | Open |
| WHOIS | Query IANA and TLD WHOIS servers over port 43. No shell commands are used. | Open |
| Domain History | Show the current WHOIS and DNS snapshot. Historical third-party archives are not fetched. | Open |
| Tool | Description | |
|---|---|---|
| SMTP Tester | Connect to MX hosts on 25/465/587 and read banners. Mail is never sent. | Open |
| Email Header Analyzer | Parse Received, From, Authentication-Results and related fields from pasted headers. | Open |
| Email Security Check | Inspect the domain side of an address: MX, SPF, DKIM, DMARC and MX IP lists. | Open |
| Mail spam score | Each run issues a one-shot address on the catch-all domain. Mail sent there, or a pasted source, is scored 0–10 from SPF/DKIM/DMARC, PTR and blacklists. Mail is never sent outbound. | Open |
| Email deliverability | Score the domain side of an address without receiving a message: MX, SPF, DKIM, DMARC, PTR and the MX IP blacklist. | Open |
| Tool | Description | |
|---|---|---|
| IP Lookup | Resolve reverse DNS and IP WHOIS for a public address. Empty input uses your client IP. | Open |
| Subnet / CIDR Calculator | Calculate network address, broadcast, netmask and usable host count for an IPv4 or IPv6 prefix. Private ranges are allowed. | Open |
| Reverse IP | Resolve PTR for an IP and confirm the hostname points back. A full same-server neighbour list needs a passive-DNS provider and is not invented here. | Open |
| IP Blacklist | Query a small set of public IPv4 DNSBLs. Private addresses are rejected. | Open |
| Ping | Measure TCP connect time to ports 80 and 443. ICMP is not used. | Open |
| IP WHOIS | Query ARIN/RIPE style WHOIS for a public IP allocation. | Open |
| Port Checker | Probe an allow-list of common ports on a public host. Arbitrary port ranges are rejected. | Open |
| MAC Lookup | Identify a short built-in OUI table and unicast / locally-administered bits. | Open |
| ASN Lookup | Query AS number registration data from RADB WHOIS. | Open |
| Traceroute | Resolve the host and time a TCP/443 connect. Hop-by-hop ICMP traceroute is not performed. | Open |
| Latency Test | Take several TCP/443 samples and report average latency and loss. | Open |
| Bandwidth Test | Returns a payload size hint so the browser can estimate throughput against this origin. | Open |
| Tool | Description | |
|---|---|---|
| SSL Checker | Read the peer certificate: issuer, subject, validity window and SAN names. | Open |
| HTTP Headers | Issue a HEAD request and score HSTS, CSP, X-Frame-Options and related headers. | Open |
| URL Redirect Checker | Follow a short HTTP redirect chain and list each hop. Private hosts are blocked. | Open |
| Tool | Description | |
|---|---|---|
| IPv4 to IPv6 | Convert an IPv4 address to IPv4-mapped and NAT64 IPv6 notations. | Open |
| IPv6 Compress | Show compressed and fully expanded forms of an IPv6 address. | Open |