Free network engineer toolkit
DNS lookup, WHOIS, port checks, SSL/TLS inspection, CIDR and subnet math, SPF/DMARC parsing — 29 fast, focused tools. No signup, no install. Ad-supported so it stays free.
- Tools
- 29
- Categories
- 5
- Cost
- Free
Categories
View all tools →DNS & Domain
Resolve records, check propagation, look up WHOIS.
4 tools
IP & Routing
Geolocation, ASN ownership, CIDR / subnet math.
8 tools
Connectivity & Diagnostics
TCP probes, HTTP headers, TLS, redirects.
4 tools
Email & Security
SPF, DMARC, DKIM, MX, blacklists.
6 tools
Utilities
Encoders, hashes, parsers, password generator.
7 tools
Popular tools
View all tools →DNS Lookup
Look up DNS records (A, AAAA, MX, TXT, NS, SOA, CAA, SRV, CNAME) for any domain.
DNS Propagation Checker
Compare DNS answers across multiple public resolvers worldwide.
Reverse DNS (PTR) Lookup
Find the hostname assigned to an IP address, with forward-confirm verification.
Domain WHOIS Lookup
Look up registration details for a domain — registrar, dates, nameservers, status.
What's My IP
Show the public IPv4 or IPv6 address you are connecting from, with geolocation and ASN.
IP Lookup & Geolocation
Get geolocation, ISP, and ASN ownership for any IP address.
IP WHOIS Lookup
Find the network owner, ASN, and registry record for any IP.
ASN Lookup
Look up the AS number behind an IP, or details for any ASN.
CIDR Calculator
Calculate network, broadcast, range, and host count for an IPv4 CIDR.