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://slack.github.com 200 1 hop 871 ms

Final response headers (21)

content-security-policy	default-src 'none';style-src 'unsafe-inline' 'self' https://fonts.googleapis.com;font-src 'self' https://fonts.gstatic.com;img-src 'self';media-src 'self';script-src 'self';connect-src 'self';base-uri 'self';form-action 'self';frame-ancestors 'self';object-src 'none';script-src-attr 'none';upgrade-insecure-requests
cross-origin-opener-policy	same-origin
cross-origin-resource-policy	same-origin
origin-agent-cluster	?1
referrer-policy	same-origin
strict-transport-security	max-age=31536000; includeSubDomains
x-content-type-options	nosniff
x-dns-prefetch-control	off
x-download-options	noopen
x-frame-options	DENY
x-permitted-cross-domain-policies	none
x-xss-protection	0
x-powered-by	Express
content-type	text/html; charset=utf-8
content-length	52182
etag	W/"cbd6-Rs4X08KrnpCMhRVAHlb8E5hvqtM"
date	Sat, 31 Oct 2026 17:34:19 GMT
x-github-backend	Kubernetes
x-github-request-id	D2F0:49277:8FEFB26:9B78367:6AE6269B
x-github-edge-region	iad
server	github.com

Tech stack

X-Powered-By: Express

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=slack.github.com

curl -s '/api/v1/http/headers?q=slack.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