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://books.timgraham.dev/login?next=%2F 200 2 hops 3756 ms
Redirect chain
  1. 302 https://books.timgraham.dev 1680 ms
  2. 200 https://books.timgraham.dev/login?next=%2F 1070 ms
Final response headers (12)
alt-svc h3=":443"; ma=2592000
content-security-policy default-src 'self' 'unsafe-inline' 'unsafe-eval'; font-src 'self' data:; connect-src 'self' assets.hardcover.app; img-src 'self' data:; object-src 'none';
content-type text/html; charset=utf-8
date Wed, 10 Jun 2026 04:08:35 GMT
set-cookie session=eyJjc3JmX3Rva2VuIjoiNzg4N2UyYzExMDgzYWRhNzZhZTc4ZDY2NzY4ZGE0ZWI3NTk3YzJmZCJ9.aijjQw.xeJl9mrAwA1MxqKdeUgKWV1sXIqAS4nHD5eJ5dQgHKw; HttpOnly; Path=/; SameSite=Lax
strict-transport-security max-age=31536000
vary Cookie
via 1.1 Caddy
x-content-type-options nosniff
x-frame-options SAMEORIGIN
x-xss-protection 1; mode=block
content-length 7815
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=books.timgraham.dev 
curl -s '/api/v1/http/headers?q=books.timgraham.dev'
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