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://mona-arcade.github.com 404 1 hop 95 ms
Final response headers (18)
server GitHub.com
content-type text/html; charset=utf-8
etag W/"6aa9aa5f-239b"
content-security-policy default-src 'none'; style-src 'unsafe-inline'; img-src data:; connect-src 'self'
content-encoding gzip
x-github-request-id A976:2A6E4D:F47886:F5CF5E:6AA9C56C
x-github-edge-region fra
accept-ranges bytes
date Tue, 15 Sep 2026 23:09:50 GMT
via 1.1 varnish
age 2769
x-served-by cache-fra-etou8220175-FRA
x-cache HIT
x-cache-hits 1
x-timer S1789513791.530755,VS0,VE1
vary Accept-Encoding
x-fastly-request-id 9b4bb677cd166613763bbd102803ff76e77a47d9
content-length 5142
Tech stack
Fastly
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=mona-arcade.github.com 
curl -s '/api/v1/http/headers?q=mona-arcade.github.com'
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