Guides • 6 min
Understanding security headers in the real world
What CSP, HSTS, X-Frame-Options, and cookie flags actually tell you — and what they don’t.
Dec 2025
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Instant intelligence for domains, IPs & HTTP
• fast • shareable • developer-first
Site Info Check tools
Analyze DNS, IP addresses, HTTP behavior, and domain WHOIS instantly — with clean outputs that are easy to understand, export, and share with your team.
Free
Core tools
JSON
Consistent output
TLS
Security insights
Fast
Minimal friction
Example output highlights
HTTP and SSL posture
Headers, redirects, HSTS, cookies, TLS chain & more.
Domain identity
WHOIS metadata, registrar, nameservers, status codes.
Network context
IP geodata, ASN/ISP, reverse DNS, risk signals (where available).
Tip
Build reports faster by copying the output blocks into tickets, docs, or incident notes.
Core Tools
Purpose-built modules with clear results, thoughtful UI, and consistent fields.
Pro UX: fast feedback • predictable outputs • readable errors
IP Info
Geolocation, ISP/organization, ASN context, reverse DNS, and quick signals that help you triage faster.
Open IP Info →
IPv4 • IPv6
HTTP Info
Headers, security headers, redirect chains, cookies, HTTP versions, and TLS/certificate insights.
Open HTTP Info →
Headers • TLS • Status
Domain Info
Registrar, creation/expiry dates, nameservers, statuses, and registration footprint.
Open Domain Info →
Registrar • NS • Dates
How it works
A simple flow designed for speed — with clean outputs and clear failure states.
1
Enter a target
Domain, URL, IPv4 or IPv6 (depending on the tool).
2
We query multiple sources
Network, DNS, headers, TLS chain, WHOIS — where applicable.
3
You get a readable report
Well-structured sections + consistent fields + share-ready output.
Designed for real workflows
Incident response
Quickly check redirects, TLS posture, and domain footprint when you’re triaging alerts.
Security reviews
Verify security headers, cookie flags, and certificate chain details in one place.
Dev debugging
Confirm server behavior, caching headers, and HTTP versions without extra tooling.
Support & ops
Identify DNS/registrar changes and share results with customers or internal teams.
Latest from the Blog
Stay updated with the latest tips on SEO, performance, and web technology.
Ops • 5 min
DNS basics: A, AAAA, MX, TXT — quick troubleshooting map
A practical way to interpret common DNS records when something “mysteriously” breaks.
Dec 2025
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Security • 7 min
WHOIS + registrar signals: what to look for during investigations
How registrar changes, nameserver shifts, and domain age can strengthen (or weaken) a hypothesis.
Dec 2025
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Ship faster with clearer site intelligence
Whether you’re debugging, investigating, or documenting — Site Info Check keeps the signal high and the noise low.