Network and web
Network and web: 7 free online tools. Compare tasks, read instructions and choose a tool. No account required.
Inspect IP addresses, DNS records, certificates, redirects and website responses. Network checks describe the response observed at the time of the request. DNS caches, firewalls and regional routing can produce different results; review the tool's data sources and limits.
Choose a tool 7
What is my IP
See your public IPv4 and IPv6 automatically, with one-click copying.
Network and webIPv4 subnet calculator
Calculate an IPv4 network, mask and address range.
Network and webIPv6 subnet calculator
Calculate an IPv6 address range with exact arithmetic.
Network and webIP address validator
Validate and normalize an IPv4 or IPv6 address.
Network and webRobots.txt tester
Test supplied crawl rules against a path and crawler.
Network and webPort number reference
Look up conventional ports for common services.
Network and webBrowser screen size
See live viewport dimensions, screen size and pixel ratio instantly.
Network and web