This tool fetches any URL and grades its HTTP security headers — HSTS, Content-Security-Policy, X-Frame-Options and more. Missing headers leave a site open to XSS, clickjacking and downgrade attacks, and increasingly hurt trust signals.
What is Security Header Checker?
A security header checker scans a site's HTTP response for the headers that protect visitors from common attacks — clickjacking, cross-site scripting, protocol downgrades, and more. It's a fast way to gauge how hardened your site is.
How it works
Security headers are server instructions that tell browsers how to behave safely — Content-Security-Policy, Strict-Transport-Security, X-Content-Type-Options, X-Frame-Options, and Referrer-Policy. The tool checks which are present and flags what's missing.
How to use this tool
Enter a URL. The checker reports which security headers are set and which are absent, so you know exactly what to add to your server or CDN configuration.
Why it matters
Missing security headers leave visitors exposed and can erode trust (and increasingly, rankings). They're usually a few lines of server config to add — a high-impact, low-effort security win that most sites overlook.
Frequently asked questions
What are the most important security headers?
Strict-Transport-Security (forces HTTPS), Content-Security-Policy (blocks injected scripts), and X-Content-Type-Options are among the highest-impact to implement first.
Do security headers affect SEO?
Indirectly — they protect users and reinforce HTTPS, which is a ranking signal. A secure, trustworthy site is what search engines want to rank.
Are these hard to add?
Usually not — most are single lines added to your server, CDN, or framework config. The checker tells you which are missing so you can add them one by one.