OWASP Webmaster Suite• Updated for 2026

HTTP Security Headers Checker & Scanner

Evaluate your website's defensive HTTP response headers in real-time. Test HSTS, Content Security Policy (CSP), X-Frame-Options, Referrer-Policy, and get instant copy-paste configs for Nginx, Apache, and Next.js.

Quick Test:

The 6 Essential Security Headers for Modern Websites

Modern browsers support powerful security primitives delivered over HTTP headers. Implementing these headers eliminates entire classes of web application vulnerabilities without modifying backend code.

Strict-Transport-Security

HSTS

Forces browsers to connect exclusively over HTTPS, preventing SSL stripping and protocol downgrade attacks. Required for browser preload lists.

max-age=31536000; includeSubDomains; preload

Content-Security-Policy

CSP

Restricts approved origins for scripts, styles, images, and fonts. Primary browser defense against Cross-Site Scripting (XSS) and data injection.

default-src 'self'; script-src 'self';

X-Frame-Options

Clickjacking

Prevents pages from being embedded in invisible iframes on malicious third-party websites, defeating UI redress and clickjacking exploits.

DENY or SAMEORIGIN

X-Content-Type-Options

MIME Defense

Blocks browsers from sniffing file content types away from the declared MIME type, preventing uploaded images or text from executing as code.

nosniff

Referrer-Policy

Privacy

Controls how much referrer information (paths, query parameters, auth tokens) is broadcast in the Referer header when navigating away from your site.

strict-origin-when-cross-origin

Permissions-Policy

Device Hardware

Explicitly enables or disables browser APIs such as microphone, camera, geolocation, and payment gateways for your site and embedded iframes.

camera=(), microphone=(), geolocation=()

Frequently Asked Questions About Security Headers

Clear answers on configuring, debugging, and maintaining enterprise-grade HTTP security headers.

HTTP security headers are directive response headers sent by your web server instructing the visitor's browser to activate built-in defensive shields. Without these headers, modern browsers run in standard compatibility mode, leaving web applications exposed to Cross-Site Scripting (XSS), clickjacking, MIME-type sniffing, and man-in-the-middle SSL-stripping attacks.

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