InstantIPCheck vs IPChecker.io
IPChecker.io is an IP location finder: it auto-detects your public addresses, maps geolocation, and lets you query another IP or hostname. InstantIPCheck does that too, and adds DNS/WebRTC leak tests, speed, Whois and a shareable diagnostic report.
Shared job: find the IP
Both sites detect IPv4 and IPv6 on load, show ISP and location, and accept an external address. That covers the “IP location finder” job IPChecker.io describes: own IP first, optional manual lookup second.
What InstantIPCheck adds
After the location sheet you can run DNS leak and WebRTC tests, inspect browser capabilities, measure speed, trace with MTR, search Whois, and export a report. Those are separate products on many other sites.