HTTP headers
HTTP /api/v1/http/headersCapture every response header, follow redirects, time each hop.
https://accounts.google.com/v3/signin/identifier?continue=https://mail.google.com/mail/u/0/&emr=1&followup=https://mail.google.com/mail/u/0/&osid=1&passive=1209600&service=mail&flowName=WebLiteSignIn&flowEntry=ServiceLogin&dsh=S-1592387099:1793426203750806
200
5 hops
285 ms
Redirect chain
-
301
https://mail.google.com36 ms -
301
https://mail.google.com/mail/26 ms -
302
https://mail.google.com/mail/u/0/45 ms -
302
https://accounts.google.com/ServiceLogin?service=mail&passive=1209600&osid=1&continue=https://mail.google.com/mail/u/0/&followup=https://mail.google.com/mail/u/0/&emr=139 ms -
200
https://accounts.google.com/v3/signin/identifier?continue=https://mail.google.com/mail/u/0/&emr=1&followup=https://mail.google.com/mail/u/0/&osid=1&passive=1209600&service=mail&flowName=WebLiteSignIn&flowEntry=ServiceLogin&dsh=S-1592387099:179342620375080665 ms
Final response headers (24)
| content-type | text/html; charset=utf-8 |
| x-frame-options | DENY |
| set-cookie | __Host-GAPS=1:O2es_XR5m0LaVv6QdWrbTQbc9p8Jzg:y4px99fVn06Z15P6; Expires=Mon, 30-Oct-2028 05:56:43 GMT; Path=/; Secure; HttpOnly; Priority=HIGH |
| vary | Sec-Fetch-Dest, Sec-Fetch-Mode, Sec-Fetch-Site |
| x-auto-login | realm=com.google&args=service%3Dmail%26continue%3Dhttps://mail.google.com/mail/u/0/ |
| link | <https://workspace.google.com/gmail/>; rel="canonical" |
| x-ua-compatible | IE=edge |
| cache-control | no-cache, no-store, max-age=0, must-revalidate |
| pragma | no-cache |
| expires | Mon, 01 Jan 1990 00:00:00 GMT |
| date | Sat, 31 Oct 2026 05:56:43 GMT |
| strict-transport-security | max-age=31536000; includeSubDomains |
| accept-ch | Sec-CH-UA-Arch, Sec-CH-UA-Bitness, Sec-CH-UA-Full-Version, Sec-CH-UA-Full-Version-List, Sec-CH-UA-Model, Sec-CH-UA-WoW64, Sec-CH-UA-Form-Factors, Sec-CH-UA-Platform, Sec-CH-UA-Platform-Version |
| report-to | {"group":"AccountsSignInUi","max_age":2592000,"endpoints":[{"url":"https://csp.withgoogle.com/csp/report-to/AccountsSignInUi"}]} |
| content-security-policy | script-src 'report-sample' 'nonce-yO45VFCejtuIDYQBu2y2eQ' 'unsafe-inline';object-src 'none';base-uri 'self';report-uri /v3/signin/_/AccountsSignInUi/cspreport;worker-src 'self', require-trusted-types-for 'script';report-uri /v3/signin/_/AccountsSignInUi/cspreport |
| cross-origin-opener-policy-report-only | same-origin; report-to="AccountsSignInUi" |
| cross-origin-resource-policy | same-site |
| permissions-policy | ch-ua-arch=*, ch-ua-bitness=*, ch-ua-full-version=*, ch-ua-full-version-list=*, ch-ua-model=*, ch-ua-wow64=*, ch-ua-form-factors=*, ch-ua-platform=*, ch-ua-platform-version=* |
| reporting-endpoints | default="/v3/signin/_/AccountsSignInUi/web-reports?context=eJwNw2tIk2EYBmB7870RsxI7qAsijEALdYqHwEhMTHBuc377PEy3pTjbQJzOzchCK3FhGgillRZWFBlaFv2JSlqRpkSzdOUOiYSHMitLUhIMei64Ai_yvYESv4xIiZ8j4gm7u_Mpe0ydZR42SQ8-8rBs-lnuZeEKL4ukbruXOV94mT3Bx2w3fCwzZZqlaWdYBvXvn2Vxqjm2dnWOdQTNs07a5HHyC_Re-igfyBnl1puj_Aw9Ry9T45H3vILG7RrjqdQS5uKnaNR-F4-mjmwXbyj6wF9FufkwNZrdfKnOzYNPuHn6iptn0sE0D-_e5-VH6318u9fHJXTE9Ym_pbd0WfiaKcN32t4tQ8MbGRrp8pQMqzTkpwzKJRnujGcjKkaOaLpSI4e_VY4FuwKLtLddgX465lXC_4cSgxM5GKG1CSokqlVIp4MVKozQj9dVMD9XoYY6Z1QYo8l9ufA4cmGczcWvbQL-0OAwAVvp7yQByzTrgAAFnS0RME__0jW6pVRAKHX1Cbi_KqBKr4aVmk-qMXVbjdQhNQK-qTEZKKI5SET-HhG1JhG760QstIhYpGK_iIcDIqpfi7DRxlERsQN5OE2baCtto5doFy0Zz0PejnxoqFifj0KaHF6AFBqaUQAJPdRbgMO0_GwhjEOFqKCtxzRoo509Glyj0y81GC4qwoaIYmymSnsxBPqvRYuwZ1r0vNNi3UYdmjfpcJ5-adLB5UgMDwkK6LJ3TCD4wcTwlfURsaXmar2pzFBpNVmPl1vMlVZDZVmJzWq0mWoMllqDRR8vjU-Kk8Ynx0gT9FXS_5sLENI" |
| content-encoding | gzip |
| server | ESF |
| x-xss-protection | 0 |
| x-content-type-options | nosniff |
| alt-svc | h3=":443"; ma=2592000,h3-29=":443"; ma=2592000 |
Tech stack
HTTP/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=mail.google.com
curl -s '/api/v1/http/headers?q=mail.google.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