Network Tools

Subnet Calculator

Paste a CIDR, a bare IP, an IP range, or a host count — get the answer plus an interactive block map.

Subnet Splitter

Divide a CIDR block into equal subnets. See the breakdown of each resulting subnet.

CIDR / IP Range Converter

Convert between CIDR notation and IP address ranges. Bidirectional converter.

IPv6 Subnet Calculator

Enter an IPv6 CIDR — or a bare address — to see the network, range, and how many /64s fit inside.

DNS Lookup

Query A, AAAA, MX, TXT, CNAME, NS, SOA, and PTR records from Cloudflare, Google, and Quad9.

DNS Propagation

Check if DNS changes have reached the major public resolvers — Cloudflare, Google, Quad9, and more.

Whois Lookup

Domain and IP registration information. See registrar, creation date, nameservers, and contacts.

Reverse DNS (PTR)

Find the hostname associated with an IP address via PTR record lookup.

SPF Record Checker

Validate SPF records for email authentication. Check syntax, DNS lookups, and mechanisms.

DMARC Record Checker

Check DMARC policy configuration. Validate tags, policy mode, and reporting addresses.

Ping / Connectivity

Check if a host is reachable and measure TCP latency to ports 80 and 443.

Traceroute

Trace the network path to a host. See each hop with IP address and round-trip latency.

Port Scanner

Scan 19 common ports (SSH, HTTP, HTTPS, databases, mail) on any host.

SSL/TLS Certificate Checker

Inspect SSL certificates. Check issuer, expiry, SANs, and chain validity for any domain.

HTTP/2 & HTTP/3 Test

Check if a website supports HTTP/2, HTTP/3 (QUIC), and which TLS version it uses.

Blacklist (RBL) Checker

Check your mail server's name or IP against major spam blacklists like Spamhaus and Barracuda.

ASN Lookup

Look up AS number, organization, country, and routing prefix for any IP or ASN.

IP Converter

Convert between dotted decimal, binary, decimal, and hexadecimal IP representations.

HTTP Headers Viewer

Inspect the HTTP request headers our server receives, or fetch any URL's response headers and security-header checklist.

Email Header Analyzer

Paste raw email headers to see if a message is legit or spoofed — analyzed in your browser.