HTTP headers
HTTP /api/v1/http/headersCapture every response header, follow redirects, time each hop.
https://www.cloudflare.com/sitemap.xml
200
1 hop
167 ms
Final response headers (20)
| date | Sat, 09 May 2026 11:05:58 GMT |
| content-type | application/xml; charset=utf-8 |
| cache-control | public, max-age=0, must-revalidate |
| etag | W/"a835169e55eaf0e4a2b37d3d207bb4d3" |
| strict-transport-security | max-age=31536000; includeSubDomains |
| permissions-policy | geolocation=(), camera=(), microphone=() |
| referrer-policy | strict-origin-when-cross-origin |
| x-content-type-options | nosniff |
| x-frame-options | SAMEORIGIN |
| x-gww-loc | EN-US |
| x-pgs-loc | EN-US |
| x-xss-protection | 1; mode=block |
| vary | accept-encoding |
| set-cookie | __cf_bm=e9ToxbtUQ6ZNEBuazXVWdL0gRp27u4OyDFUoLl2TXyo-1778324758.5803516-1.0.1.1-6zieQnVlCaWLXl7TjbZpfDOQxu8e398KsK6.bqD5.io6Lk1zN7xkjj.OjE0caR0kzaugEuFPBS78sX9z_XTzvL926zRfYUVH9VnlzS6DeYPjt1Yahrz5VmBdB5KTm.mfIIngz5Y1_MyYOqlxX1BA7A; HttpOnly; Secure; Path=/; Domain=www.cloudflare.com; Expires=Sat, 09 May 2026 11:35:58 GMT |
| report-to | {"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=06EtiSMS3ZhakXXIekC%2FdCm97Xt3QGSK7vep9%2BGqI39HGOFiXXh6tdj2j3Ny8Yua9U3I9zxuqlaFEkAxHqtURQwWmNDHsCtp9gmR%2BpcpxSJertSqVRl8s2rq8v%2BIz6nxCTp3dA%3D%3D"}]} |
| nel | {"report_to":"cf-nel","success_fraction":0.0,"max_age":604800} |
| content-encoding | br |
| server | cloudflare |
| cf-ray | 9f903b6d1d7d12f7-AMS |
| alt-svc | h3=":443"; ma=86400 |
Tech stack
CloudflareHTTP/3 (QUIC)
How to use HTTP headers
-
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
Click "Inspect"
host.tools issues real probes (DNS, HTTP, TCP, TLS, WHOIS where applicable) and renders the result in milliseconds.
-
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=https%3A%2F%2Fwww.cloudflare.com%2Fsitemap.xml
curl -s '/api/v1/http/headers?q=https%3A%2F%2Fwww.cloudflare.com%2Fsitemap.xml'
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.
- ✓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