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Security Headers Checker

Check the six response headers that harden a site against common attacks.

Free, no signup. We fetch the page once and read what your server sends back.

Fetching the page…

What this checks

Security headers are not a ranking factor. They matter because a compromised or defaced site loses rankings very quickly, and because most of these are a single line of configuration that nobody ever got round to adding.

  • Strict-Transport-Security
  • Content-Security-Policy
  • X-Content-Type-Options
  • X-Frame-Options
  • Referrer-Policy
  • Permissions-Policy

How to act on the result

  • X-Content-Type-Options: nosniff and X-Frame-Options: SAMEORIGIN are safe on almost any site.
  • Content-Security-Policy is the most valuable and the most work. Start in report-only mode.
  • Add HSTS only once you are certain HTTPS works everywhere, because it is hard to undo.

Frequently asked

Do security headers affect SEO?

Not directly. A hacked site loses rankings fast, and Google shows warnings on sites flagged as compromised, so the indirect connection is real.

Which should I add first?

X-Content-Type-Options: nosniff, X-Frame-Options: SAMEORIGIN and a Referrer-Policy. All three are low-risk one-liners.

Is HSTS risky?

It is hard to reverse. Browsers remember it for the max-age you set, so if HTTPS breaks later the site becomes unreachable. Start with a short max-age.

Do I need a Content-Security-Policy?

It is the strongest defence against cross-site scripting and the most effort to configure without breaking your own scripts. Deploy in report-only mode first.

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