HTTP headers
HTTP /api/v1/http/headersCapture every response header, follow redirects, time each hop.
https://tokencalculator.com
200
1 hop
180 ms
Final response headers (23)
| date | Sat, 09 May 2026 07:11:02 GMT |
| content-type | text/html; charset=UTF-8 |
| server | cloudflare |
| nel | {"report_to":"cf-nel","success_fraction":0.0,"max_age":604800} |
| vary | Accept-Encoding |
| referrer-policy | strict-origin-when-cross-origin, same-origin, same-origin |
| permissions-policy | geolocation=(), microphone=(), camera=(), payment=(), usb=() |
| content-security-policy | default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval' https://unpkg.com https://cdnjs.cloudflare.com; style-src 'self' 'unsafe-inline' https://cdnjs.cloudflare.com https://fonts.googleapis.com; img-src 'self' data: blob: https:; font-src 'self' data: https://cdnjs.cloudflare.com https://fonts.gstatic.com; connect-src 'self' https:; frame-src 'self'; object-src 'none'; base-uri 'self'; form-action 'self'; |
| x-cache-lifetime | 604800 |
| x-cache-tags | 9156 |
| x-cache-age | 25437 |
| pragma | no-cache |
| x-frame-options | SAMEORIGIN |
| x-content-type-options | nosniff |
| x-xss-protection | 1; mode=block |
| x-permitted-cross-domain-policies | master-only |
| x-page-speed | 1 |
| cache-control | max-age=0, no-cache, no-store |
| report-to | {"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=%2FdN%2Bcq7b6APCoVN6n88khxeOERTBHLtcYkyu%2FGQKvE9gmR%2BGYSSM%2FKGIUFf7jKOWORbimyVILc8ixO4luWauOItRraw8GjEZBWe1npjkLiKJTC6y%2BMPos%2BkUq6%2BddMdtVUzOZcYj"}]} |
| cf-cache-status | DYNAMIC |
| content-encoding | zstd |
| cf-ray | 9f8ee345cdb0fb8d-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.
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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%2Ftokencalculator.com
curl -s '/api/v1/http/headers?q=https%3A%2F%2Ftokencalculator.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.
- ✓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