A few months ago, I was reviewing the Nginx configuration of a side project and decided to run it through a security headers scanner. I pasted the response headers into a popular online tool, hit Enter, and waited.
Grade F. 12/100.
I was stunned. I had HTTPS, a valid certificate, and a modern stack. But I was missing every critical security header. No HSTS, no CSP, no X-Frame-Options. My site was a sitting duck for clickjacking, XSS, and protocol downgrade attacks, and I didn’t even know it.
That experience led me to build DevToolbox HTTP Header Analyzer — a completely client-side tool that grades your security headers from A+ to F, explains every single one in plain English, and gives you ready-to-paste fixes. And it never sends your headers to any server.
Try It Yourself in 15 Seconds
