What are Security Headers?

Security headers are HTTP response headers that tell the browser how to behave when loading your page. They help prevent common attacks (clickjacking, XSS, protocol downgrade) and signal to users and search engines that your site takes security seriously.

Why security headers matter

• Trust and safety — Browsers and security tools use headers to grade your site. Missing or weak headers can trigger warnings or lower trust signals.
• SEO and Core Web Vitals — Some headers (e.g. HSTS, preload) can affect how your site is fetched and cached, which can indirectly support performance and indexing.
• Compliance — Certain industries or frameworks (e.g. PCI, OWASP) recommend or require specific headers.

Common security headers

• Strict-Transport-Security (HSTS) — Tells the browser to only use HTTPS for your domain. Reduces risk of downgrade attacks and mixed content.
• Content-Security-Policy (CSP) — Restricts which sources can load scripts, styles, and other resources. Helps mitigate XSS and injection.
• X-Frame-Options — Controls whether your page can be embedded in an iframe. Helps prevent clickjacking.
• X-Content-Type-Options — Set to nosniff so the browser doesn’t guess MIME types, reducing some attack surface.
• Referrer-Policy — Controls how much referrer information is sent when users click links.

How BearAudit checks them

BearAudit fetches each crawled page and inspects the response headers. We report which security headers are present, missing, or misconfigured, and assign a per-page security grade from A+ to F. You can see the grade and details in the page viewer and in exports, so you can fix issues site-wide or page-by-page.

This is part of our technical SEO and security checks: we focus on the stuff that actually matters for crawlability, indexing, and user trust.