Network & Web Tools
HTTP Headers Checker Online Free
Inspect response headers and review common web security headers for a public URL.
About this tool
HTTP response headers describe caching, content type, redirects, server behavior and browser security policies. This checker displays the headers returned by a public page and highlights several commonly reviewed security headers. Presence alone does not prove that a policy is correctly configured.
Common use cases
- ✓ Check Content-Security-Policy and HSTS deployment.
- ✓ Inspect cache-control and content-type behavior.
- ✓ Troubleshoot proxy, CDN or redirect configuration.
- ✓ Compare headers before and after a release.
How to use it
- Enter the public URL you want to inspect.
- Run the checker and review the complete header list.
- Check the highlighted security-header section.
- Validate policy values with your application and security requirements.
Important interpretation notes
- • Security headers must be configured correctly, not merely present.
- • A server may return different headers for authenticated sessions or other paths.
- • This is an informational check rather than a penetration test.
Related Network & Web Tools
Frequently asked questions
What is Content-Security-Policy?
CSP restricts which resources a browser may load and can reduce some injection risks when configured carefully.
What is HSTS?
Strict-Transport-Security tells supporting browsers to prefer HTTPS for a defined period.
What does X-Content-Type-Options do?
The nosniff value reduces MIME type guessing in supported browsers.
Why are some headers missing?
They may not be configured for that path, proxy or environment.
Does every website need identical headers?
No. Policies should match the application, content and deployment model.
Does this tool change headers?
No. It only displays the headers returned to the server-side request.