Network tools
Free lookups you can run against any domain or address. Nothing here is stored,
and nothing is fetched until you press the button. Each tool has its own page so
the result you came for is not buried under five others.
Look up & diagnose
- DNS records — A, AAAA, CNAME,
MX, NS, TXT and CAA, plus the SPF and DMARC policy that decides whether a domain
can send mail.
- HTTP status and security headers
— the redirect chain and the headers that matter: HSTS, CSP,
X-Frame-Options, Referrer-Policy.
- TLS certificate — the
certificate a server really presents: issuer, validity, names, and whether it
matches the host you asked for.
- AdSense & analytics checker —
which advertising and tracking scripts a site loads, and whether its
ads.txt authorises them.
- Traceroute on a globe — the actual
route from our server to an address, hop by hop, drawn on a globe.
- Cloudflare bot protection checker —
send one plain no-JavaScript request to a site and see whether Cloudflare
challenges it, blocks it, or lets it through. The honest way to test Bot Fight
Mode after switching it on.
Explore & compare
- IP Duel — two addresses side by side:
country, network, distance and time offset.
- Time machine — what a domain used to
resolve to, and what changed.
- IPv4 blocks by country — every country's
allocated and assigned IPv4 space, collapsed into the smallest possible list of
CIDR blocks, straight from the five RIRs' own statistics.
- Address of the day — one notable
address or prefix a day, with the story behind it and the source it came
from.
- Watchlist — keep addresses in
your browser and see at a glance what changed since you last looked.
Your connection & the API
- What sites see about you — the
headers and fingerprints your browser hands over.
- Why is my location wrong? — how we
place an address, why a lookup can be off, and how to tell us when it is.
- Connection card — your own address as
a shareable card you can post anywhere.
- Read-only API — JSON for any IP or
domain, from local data, cached. Not public: a Google ID token
on an allowlisted account is required.
- Embeddable badge — a live SVG badge of
the visitor's address for your own site.
- Email alerts — watch an address or
domain and get one plain-text mail when it changes. Double opt-in, one-click
stop.
What is not here
No ping, no port scan and no vulnerability check: those read as offensive tooling,
and the app runs without the raw-socket privilege traceroute needs anyway. The
traceroute we do run is a real measurement from this one server, not a scan of
yours.
Related games
All twelve games are indexed on their own page. The same
data, as a puzzle: Odd One Out puts eight addresses in
a grid and asks which one cannot exist, IPv4 Land Grab asks
who was handed a /8, Higher or Lower turns two countries'
prefix counts into a two-second question,
Public or Reserved?
asks whether an address is routable at all,
Longest Prefix Match puts a routing table in front of
you, and Ping Detective shows that a latency bounds a
distance but never a position.