Security Headers
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Instantly analyze any website's HTTP security headers. Get a detailed grade from A+ to F with actionable recommendations.
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Header Analysis
Click a header for detailsFix These Issues Automatically
ShieldFlow continuously monitors your security headers, detects misconfigurations, and helps you enforce the right policies - all from a single dashboard.
How It Works
Three steps to a complete security headers audit
Enter a URL
Enter any public website URL. We support HTTP and HTTPS sites with automatic redirect following.
We Analyze Headers
Our scanner fetches the site's HTTP response and analyzes 9 critical security headers against best practices.
Get Your Report
Receive a detailed report with an overall grade, per-header analysis, and specific recommendations to improve.
Why Security Headers Matter
Security headers are your first line of defense against client-side attacks. Without them, your users are exposed.
Cross-Site Scripting (XSS)
CSP prevents attackers from injecting malicious scripts into your pages. Without it, any input field could become an attack vector.
Clickjacking
X-Frame-Options and frame-ancestors prevent your site from being embedded in malicious iframes that trick users into unintended actions.
Protocol Downgrade
HSTS forces HTTPS connections, preventing attackers from intercepting traffic through protocol downgrade or SSL stripping attacks.
MIME Sniffing
X-Content-Type-Options prevents browsers from interpreting files as a different MIME type, blocking drive-by download attacks.
Information Leakage
Referrer-Policy controls what URL information is shared when users navigate away, protecting sensitive paths and query parameters.
Unauthorized Features
Permissions-Policy restricts which browser APIs (camera, microphone, geolocation) can be used, limiting the impact of compromised scripts.
Frequently Asked Questions
HTTP security headers are directives sent by a web server in HTTP responses that instruct browsers how to behave when handling your site's content. They form a critical defense layer against common web attacks like cross-site scripting (XSS), clickjacking, MIME-type sniffing, and protocol downgrade attacks. Properly configured security headers can prevent the majority of client-side vulnerabilities.
At minimum, every website should implement these six essential headers: Content-Security-Policy (CSP) to control resource loading, Strict-Transport-Security (HSTS) to enforce HTTPS, X-Content-Type-Options to prevent MIME sniffing, X-Frame-Options to block clickjacking, Referrer-Policy to control information leakage, and Permissions-Policy to restrict browser features. Advanced sites should also add COOP, COEP, and CORP for full cross-origin isolation.
Yes, the ShieldFlow Security Headers Scanner is completely free with no account required. You can scan any public website as many times as you need. For continuous monitoring, automated fixes, and team collaboration, check out our paid plans.
An A+ (95-100) means excellent security header configuration with all headers properly set. A (85-94) is great with minor improvements possible. B (70-84) indicates good coverage but some headers need attention. Scores below C (55) indicate significant security gaps that leave your users vulnerable to common web attacks.
Security headers are configured on your web server (Nginx, Apache, IIS), CDN (Cloudflare, AWS CloudFront), or application framework (.NET, Express, Django). Each platform has different configuration methods. ShieldFlow simplifies this by detecting your current headers, recommending the right values, and helping you deploy them through our SDK or middleware - with continuous monitoring to catch regressions.
No. The scanner makes a single HTTP request to the URL you provide, analyzes the response headers, and returns the results to your browser. We do not store the scanned URLs, results, or any other data. The analysis happens in real-time and nothing is persisted.
Don't Just Scan - Protect
ShieldFlow monitors your security headers 24/7, alerts you to regressions, and helps you enforce the right policies across all your applications.