Security Headers Checker
Grade a website's HTTP security headers like HSTS, CSP, X-Frame-Options and Referrer-Policy from A+ to F, with fixes. Free tool.
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How to use Security Headers Checker
- Enter your site's address.
- Get a grade from A+ to F and a list of missing or weak headers.
- Add the missing headers in your server or CDN settings.
Good to know
- Our server fetches the page for you (browsers block reading other sites directly). Only public websites can be checked — private and local network addresses are refused.
Privacy
Your file or request is processed on our server, then deleted as soon as the result is sent back. Nothing is kept or shared.
Questions
Which header matters most?
Strict-Transport-Security (forces HTTPS) and Content-Security-Policy (limits what scripts can run) give the biggest protection.