Networking Tools
A growing kit of 26 free tools for setting up, securing, and understanding your home network.
IP & Subnetting
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What's My IP
Instantly see your public IPv4 and IPv6 addresses, plus location, ISP, and a map.
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Subnet Calculator
Enter an IP and prefix to get the network, broadcast, host range, mask, and host count.
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CIDR Cheat Sheet
Full /0-/32 reference of prefixes, subnet masks, host counts, and wildcard masks, plus a converter.
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IP Address Checker
Find out if an IP is public, private, loopback, CGNAT, link-local, or reserved.
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IP Format Converter
Convert an IPv4 address between dotted decimal, integer, hex, and binary, with a per-octet breakdown.
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DHCP Pool Planner
Carve a subnet into static and DHCP ranges and see exactly how many addresses each gets.
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IPv6 Calculator
Expand or compress an IPv6 address and see its network, range, and type for any prefix length.
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WiFi & Wireless
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WiFi Channel Guide
See why 2.4GHz channels 1, 6, and 11 don't overlap, and how to pick 5GHz channels and widths.
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WiFi Password Generator
Create strong random passwords or memorable passphrases right in your browser.
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WiFi QR Code Generator
Turn your network name and password into a QR code guests can scan to connect instantly.
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WiFi Signal Strength Guide
Understand WiFi signal strength in dBm - what's good, what's weak, and what to expect at each level.
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Connection & Reference
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Data Usage Estimator
Estimate your monthly internet data use from streaming, gaming, calls, and browsing habits.
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Download Time Calculator
See how long a download takes at a given speed - and the real MB/s behind a Mbps plan.
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Ethernet Cable Guide
Compare Cat5e, Cat6, Cat6a, Cat7, and Cat8 by speed and distance, and get a recommendation.
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Ethernet Termination Guide
Wire an RJ45 plug correctly with T568A/T568B colour diagrams, the full pin order, and crimping steps.
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Common Ports Lookup
Search common network ports and the services that use them - handy for port forwarding.
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Router Password Finder
Search default usernames and passwords across hundreds of router models by brand, model, or IP.
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Lookups & Diagnostics
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DNS Lookup
Resolve A, AAAA, MX, TXT, CNAME, NS, SOA, CAA, and reverse (PTR) DNS records for any domain.
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SSL Certificate Checker
Inspect a site's TLS certificate: issuer, expiry, SANs, chain, and whether it validates.
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HTTP Header Checker
See a URL's response headers and grade its security headers (HSTS, CSP, X-Frame-Options, and more).
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DNSBL Blacklist Checker
Check whether an IP address is listed on common email blocklists like Spamhaus and SpamCop.
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WHOIS Lookup
Look up registration details for a domain or IP via RDAP: registrar, dates, status, and nameservers.
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Open Port Checker
Test whether a TCP port is open and reachable from the internet - the classic port forwarding check.
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DNS Propagation Checker
Query multiple public DNS resolvers at once to see whether a record has propagated worldwide.
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Email Auth Checker
Check a domain's SPF, DMARC, and DKIM records to see if its email is set up to pass authentication.
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MAC Address Lookup
Identify the manufacturer behind a MAC address from its OUI prefix - handy for auditing devices.
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