host.tools

HTTP headers

HTTP /api/v1/http/headers

Capture every response header, follow redirects, time each hop.

Try: https://host.com https://checkhost.com https://hostinfo.com https://crypt.tools
Related: DNS lookup (dig) DNS propagation Domain WHOIS SSL certificate inspector HTTP headers Security headers grader MX lookup SPF tester DMARC tester
https://dns.google/ 200 2 hops 93 ms
Redirect chain
  1. 302 https://mpo.core.polyseme.app 61 ms
  2. 200 https://dns.google/ 15 ms
Final response headers (17)
content-security-policy object-src 'none';base-uri 'self';script-src 'nonce-iLsNxW71vJewyAqk4UrCIg' 'strict-dynamic' 'report-sample' 'unsafe-eval' 'unsafe-inline' https: http:;report-uri https://csp.withgoogle.com/csp/honest_dns/1_0;frame-ancestors 'none'
strict-transport-security max-age=31536000; includeSubDomains; preload
x-content-type-options nosniff
content-security-policy-report-only script-src 'none'; form-action 'none'; frame-src 'none'; report-uri https://csp.withgoogle.com/csp/scaffolding/ntdsgswbsc:55:0
cross-origin-opener-policy-report-only same-origin; report-to=ntdsgswbsc:55:0
report-to {"group":"ntdsgswbsc:55:0","max_age":2592000,"endpoints":[{"url":"https://csp.withgoogle.com/csp/report-to/scaffolding/ntdsgswbsc:55:0"}],}
content-encoding gzip
server scaffolding on HTTPServer2
content-length 721
x-xss-protection 0
x-frame-options SAMEORIGIN
date Sat, 09 May 2026 08:00:06 GMT
expires Sat, 09 May 2026 08:05:06 GMT
cache-control public, max-age=300
content-type text/html; charset=UTF-8
age 232
alt-svc h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
Tech stack
HTTP/3 (QUIC)
How to use HTTP headers
  1. 1
    Paste your input

    Enter the value at the top — domain, IP, URL, email, ASN, hash, whatever fits this tool. The smart input auto-detects type.

  2. 2
    Click "Inspect"

    host.tools issues real probes (DNS, HTTP, TCP, TLS, WHOIS where applicable) and renders the result in milliseconds.

  3. 3
    Open the API tab

    Every web tool has a sibling /api/v1/http/headers JSON endpoint with the same payload. One copy-as-curl click and you're scripting it.

Why this matters

Headers are how the modern web declares its security posture. Auditing them is the highest-ROI thing you can do this week.

API equivalent
/api/v1/http/headers?q=mpo.core.polyseme.app 
curl -s '/api/v1/http/headers?q=mpo.core.polyseme.app'
Embed this tool
<iframe src="/http/headers?q={INPUT}&embed=1"
  width="100%" height="600" frameborder="0"></iframe>

Drop into any HTML page. The embed=1 flag hides nav and footer.

FAQ · HTTP headers

Common questions

Is HTTP headers free?
Yes — every tool is free on the web with a 200/hour rate limit per IP. The matching API endpoint /api/v1/http/headers is free up to 100 requests/hour, no key required.
Where does the data come from?
Real-time probes against authoritative sources (DNS root, RIRs, registries, the target server itself), plus partner data feeds from hostinfo.com (GeoIP/ASN) and hostcheck.com (reputation).
How fresh are the results?
Live by default. Cached for 5 minutes to make repeat queries instant; pass ?nocache=1 for a forced refresh.
Can I run this from the command line?
Yes — every tool ships with a copy-as-curl. There's also an official CLI: host.tools http headers YOUR_INPUT.
Can I monitor results over time?
Pro tier lets you schedule any tool to run every 1/5/15/60 min and alert on diff. See monitors.
host.tools Pro

Run HTTP headers on a schedule. Get pinged when it changes.

Pro gets you bulk lookups, monitors, webhook alerts, history, exports and 10,000 API calls/day. $19/mo.

See pricing Tour monitors
  • ✓Schedule any tool — every 1, 5, 15, 60 min
  • ✓Diff against last run, alert on change
  • ✓Webhook + email + Slack + PagerDuty + OpsGenie
  • ✓Bulk CSV upload, 1,000 inputs per job
  • ✓Export results as CSV / NDJSON / Excel
  • ✓90-day history, comparison view