HTTP Headers Checker
Inspect the full HTTP response headers of any URL — grouped into security, caching, content and server categories. Spot missing security headers, debug caching issues, audit server fingerprints.
What powers the HTTP Headers Checker
Full response headers from any URL
Auto-grouped by category: security, caching, content, server, other
Security header audit — HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, CORP/COEP
Status code with traffic-light coloring
Response time in ms
Final URL shown if request was redirected
Copy all headers as plain text
Why the HTTP Headers Checker is different
Browser-native
The HTTP Headers Checker runs entirely in your browser. Input is processed locally — never uploaded, never logged, never cached anywhere outside your device.
No artificial limits
No daily quotas, no character ceilings, no "upgrade for more" walls. Every feature is the complete feature — the same on the first use as the thousandth.
Production-grade quality
Built to the same engineering bar as paid SaaS tools — accurate algorithms, audited logic, responsive design and accessibility-tested interactions.
Common use contexts
- Pre-launch security header audit on a new site
- Debugging cache misses on a CDN-hosted page
- Verifying CSP, HSTS and X-Frame-Options are correctly set after deployment
- Identifying which server / framework powers a competitor site
Private and secure
Zero upload
All processing happens in your browser. Input is never transmitted, logged or cached.
Works offline
Once the page loads, the tool runs without an internet connection. No network calls happen during use.
No tracking
No accounts, no cookies for tool state. Only aggregate analytics count visits at the page level.