HeaderGuard Security Headers Checker - Free Security Headers Test Tool

Analyze your website security headers online. Check Content-Security-Policy, Strict-Transport-Security (HSTS), X-Frame-Options, X-Content-Type-Options, Referrer-Policy & Permissions-Policy. Get security headers best practices and implementation guide for Nginx, Apache, Node.js, and WordPress.

security headers checker HTTP security headers CSP validator HSTS configuration website security scan
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OWASP Compliant
SSRF Protected

Scanning your website security headers...

Analyzing HTTP security headers including CSP, HSTS, X-Frame-Options

example.com

Scanned on January 15, 2025 at 10:30 AM

Score: 95/100

50,000+
Security Scans Performed
6
Security Headers Analyzed
100%
Free & No Registration
4.9/5
User Rating

Why Use HeaderGuard Security Headers Checker?

Comprehensive HTTP security headers analysis with actionable insights. Our security headers test tool helps you identify missing security headers vulnerability and provides security headers best practices for implementation.

Detailed Security Headers Analysis

Get in-depth analysis of all critical security headers including Content-Security-Policy header, Strict-Transport-Security header, X-Frame-Options header, X-Content-Type-Options header, Referrer-Policy header, and Permissions-Policy header with specific recommendations.

Security Headers Grading System

Clear A+ to F grading helps you understand your website security headers posture at a glance. Our security headers checklist 2026 ensures comprehensive coverage of all security headers for website.

Historical Security Headers Tracking

Track your security headers implementation improvements over time with historical scan results. Monitor your HTTP security headers configuration changes and security hardening progress.

SSRF Protection & Security

Built-in security measures prevent scanning of internal or private networks. Our security headers checker includes domain validation and prevents security headers not configured vulnerabilities.

Fast & Reliable HTTP Headers Test

Quick security headers scan with caching for repeated requests and timeout handling. Our website security scan tool provides instant results for check security headers online queries.

Mobile Friendly Security Headers Tool

Fully responsive design works perfectly on all devices and screen sizes. Access our HTTP headers test tool from anywhere for website vulnerability assessment.

Complete Guide to HTTP Security Headers 2026

Security headers are HTTP response headers that help protect websites from common web vulnerabilities like XSS (Cross-Site Scripting), clickjacking, MIME sniffing, and data leakage. Proper security headers implementation is essential for website security hardening and web application security audit.

What are Security Headers?

Security headers are part of the HTTP response that web servers send to browsers. These secure HTTP headers instruct the browser on how to behave when handling your website's content. The main security headers for website protection include:

  • Content-Security-Policy (CSP) - Prevents XSS attacks by controlling resource loading
  • Strict-Transport-Security (HSTS) - Forces HTTPS connections to prevent protocol downgrade
  • X-Frame-Options - Prevents clickjacking by controlling iframe embedding
  • X-Content-Type-Options - Prevents MIME type sniffing attacks
  • Referrer-Policy - Controls referrer information sent with requests
  • Permissions-Policy - Controls browser features and APIs access

Why are Security Headers Important?

Security headers are important because they provide an additional layer of protection against common web vulnerabilities. Here's why security headers implementation matters:

  • Prevent XSS Attacks: Content-Security-Policy header helps prevent cross-site scripting by specifying which scripts can execute
  • Protect Against Clickjacking: X-Frame-Options header prevents your site from being embedded in malicious iframes
  • Prevent MIME Sniffing: X-Content-Type-Options header stops browsers from guessing file types, preventing potential security issues
  • Enforce HTTPS: HSTS configuration ensures all connections use encrypted HTTPS
  • Control Data Leakage: Referrer-Policy header limits information shared with third parties
  • Restrict Browser Features: Permissions-Policy header controls access to sensitive APIs

Security Headers Checklist 2026

Use this security headers checklist to ensure comprehensive website security:

Content-Security-Policy

Implement strict CSP with default-src, script-src, style-src directives. Avoid 'unsafe-inline' when possible.

Strict-Transport-Security

Set max-age to at least 31536000 (1 year), include includeSubDomains and preload directives.

X-Frame-Options

Use DENY for maximum protection or SAMEORIGIN if embedding is needed within your domain.

X-Content-Type-Options

Set to 'nosniff' to prevent MIME type sniffing attacks on your website.

Referrer-Policy

Use 'strict-origin-when-cross-origin' for balanced privacy and functionality.

Permissions-Policy

Disable unused features like geolocation, microphone, camera with empty parentheses ().

Content-Security-Policy (CSP) Configuration Example

Content-Security-Policy is the most important security header for preventing XSS attacks. Here's a CSP configuration example for different scenarios:

# Basic CSP Configuration Content-Security-Policy: default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' https:; font-src 'self'; connect-src 'self'; frame-ancestors 'none'; # Strict CSP (Recommended) Content-Security-Policy: default-src 'none'; script-src 'self'; style-src 'self'; img-src 'self' https:; font-src 'self'; connect-src 'self'; frame-ancestors 'none'; base-uri 'self'; form-action 'self'; # CSP with Nonce (Advanced) Content-Security-Policy: script-src 'nonce-abc123' 'strict-dynamic'; object-src 'none'; base-uri 'none';

How to Enable HSTS (Strict-Transport-Security)

HSTS configuration forces browsers to use HTTPS connections. Here's how to enable HSTS on your website:

# HSTS Header Configuration Strict-Transport-Security: max-age=31536000; includeSubDomains; preload # max-age: Time in seconds (31536000 = 1 year) # includeSubDomains: Apply to all subdomains # preload: Submit to HSTS preload list

After configuring HSTS, submit your domain to the HSTS preload list for maximum protection.

X-Frame-Options Header - Fix Clickjacking Vulnerability

X-Frame-Options header prevents clickjacking attacks by controlling whether your site can be embedded in iframes:

# Maximum Protection X-Frame-Options: DENY # Allow Same Origin Only X-Frame-Options: SAMEORIGIN # Allow Specific Domain (Deprecated, use CSP frame-ancestors) X-Frame-Options: ALLOW-FROM https://trusted-domain.com

X-Content-Type-Options - Prevent MIME Sniffing

X-Content-Type-Options header prevents browsers from MIME sniffing, which can lead to security vulnerabilities:

X-Content-Type-Options: nosniff

Referrer-Policy Header Configuration

Referrer-Policy controls how much referrer information is sent with requests:

# Recommended for most websites Referrer-Policy: strict-origin-when-cross-origin # Other options: # no-referrer # no-referrer-when-downgrade # origin # origin-when-cross-origin # same-origin # strict-origin # unsafe-url

Permissions-Policy Header

Permissions-Policy controls which browser features and APIs can be used:

Permissions-Policy: geolocation=(), microphone=(), camera=(), payment=(), usb=(), magnetometer=(), gyroscope=(), accelerometer=()

How to Add Security Headers in Nginx

Nginx security headers configuration example for complete security headers implementation:

# Nginx Security Headers Configuration server { add_header Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' https:; font-src 'self'; connect-src 'self'; frame-ancestors 'none';" always; add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always; add_header X-Frame-Options "DENY" always; add_header X-Content-Type-Options "nosniff" always; add_header Referrer-Policy "strict-origin-when-cross-origin" always; add_header Permissions-Policy "geolocation=(), microphone=(), camera=()" always; }

Security Headers in Apache Configuration

Apache security headers configuration using .htaccess or httpd.conf:

# Apache Security Headers (.htaccess or httpd.conf) <IfModule mod_headers.c> Header always set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline';" Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" Header always set X-Frame-Options "DENY" Header always set X-Content-Type-Options "nosniff" Header always set Referrer-Policy "strict-origin-when-cross-origin" Header always set Permissions-Policy "geolocation=(), microphone=(), camera=()" </IfModule>

Security Headers in Node.js/Express.js

Security headers implementation in Node.js using Express.js and helmet middleware:

# Install helmet package npm install helmet # Express.js Security Headers Configuration const express = require('express'); const helmet = require('helmet'); const app = express(); # Basic helmet configuration app.use(helmet()); # Custom CSP configuration app.use(helmet.contentSecurityPolicy({ directives: { defaultSrc: ["'self'"], scriptSrc: ["'self'"], styleSrc: ["'self'", "'unsafe-inline'"], imgSrc: ["'self'", "https:"], connectSrc: ["'self'"], fontSrc: ["'self'"], frameAncestors: ["'none'"] } })); # Custom HSTS configuration app.use(helmet.hsts({ maxAge: 31536000, includeSubDomains: true, preload: true }));

Best Security Headers for WordPress

Security headers for WordPress can be added via .htaccess, plugins, or functions.php:

# WordPress .htaccess Security Headers <IfModule mod_headers.c> Header set Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline';" Header set Strict-Transport-Security "max-age=31536000; includeSubDomains" Header set X-Frame-Options "SAMEORIGIN" Header set X-Content-Type-Options "nosniff" Header set Referrer-Policy "strict-origin-when-cross-origin" </IfModule> # WordPress Plugin Options: # - HTTP Headers # - Security Headers # - WP Security Audit Log

How to Fix Missing Security Headers Vulnerability

To fix missing security headers vulnerability, follow these steps:

  1. Identify Missing Headers: Use our security headers checker tool to scan your website and identify which security headers are not configured
  2. Choose Implementation Method: Select the appropriate method based on your server (Nginx, Apache, IIS) or framework (Node.js, PHP, WordPress)
  3. Add Security Headers: Implement the security headers using the configuration examples provided above
  4. Test Configuration: Use our HTTP headers test tool to verify all security headers are properly set
  5. Monitor & Update: Regularly check security headers and update configurations as needed

For professional assistance, consider website security hardening services or web application security audit from qualified security professionals.

Frequently Asked Questions About Security Headers

Security headers are HTTP response headers that help protect websites from common web vulnerabilities like XSS (Cross-Site Scripting), clickjacking, and MIME sniffing. Key security headers include Content-Security-Policy (CSP), Strict-Transport-Security (HSTS), X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy. These secure HTTP headers provide an additional layer of defense for website security.

You can check security headers using our free security headers checker tool. Simply enter your domain name and click scan. The tool will analyze all HTTP security headers including Content-Security-Policy, Strict-Transport-Security, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy. You'll receive a grade from A+ to F with detailed recommendations for security headers implementation.

Content-Security-Policy (CSP) is a security header that helps prevent XSS attacks by controlling which resources the browser can load. A proper CSP configuration specifies allowed sources for scripts, styles, images, fonts, and other resources. CSP is considered the most important security header for modern web application security.

To enable HSTS (Strict-Transport-Security), add the header 'Strict-Transport-Security: max-age=31536000; includeSubDomains; preload' to your server configuration. For Nginx, use add_header directive. For Apache, use Header always set. For Node.js/Express.js, use the helmet middleware. After configuration, test with our HSTS configuration checker and consider submitting to the HSTS preload list.

Security headers are important because they provide an additional layer of protection against common web vulnerabilities. They help prevent XSS attacks, clickjacking, MIME sniffing, and data leakage. Proper security headers implementation is essential for website security hardening, web application security audit, and maintaining user trust. Security headers are part of OWASP security recommendations.

To add security headers in Nginx, use the add_header directive in your server block. Example: add_header Content-Security-Policy "default-src 'self'"; add_header Strict-Transport-Security "max-age=31536000; includeSubDomains"; add_header X-Frame-Options "DENY"; add_header X-Content-Type-Options "nosniff"; Add 'always' parameter to ensure headers are sent with all responses.

Best security headers for WordPress include: Content-Security-Policy (with allowances for WordPress scripts), Strict-Transport-Security (HSTS), X-Frame-Options: SAMEORIGIN, X-Content-Type-Options: nosniff, Referrer-Policy: strict-origin-when-cross-origin, and Permissions-Policy. You can implement these via .htaccess file, security plugins, or functions.php. Test with our security headers for WordPress checker.

To fix missing security headers vulnerability: 1) Use our security headers checker to identify which headers are missing, 2) Configure missing headers in your web server (Nginx, Apache, IIS) or application framework (Node.js, Express.js, PHP), 3) Follow security headers best practices guide for proper implementation, 4) Test configuration with our HTTP headers test tool, 5) Consider website security hardening services for comprehensive security configuration.

Security headers checklist 2026 includes: Content-Security-Policy with strict directives, Strict-Transport-Security with 1-year max-age and preload, X-Frame-Options set to DENY or SAMEORIGIN, X-Content-Type-Options set to nosniff, Referrer-Policy set to strict-origin-when-cross-origin, and Permissions-Policy disabling unused features. Regular testing with security headers checker tools is recommended.

HeaderGuard provides similar security headers testing to Mozilla Observatory security test but with a focus on simplicity and actionable recommendations. Both tools check CSP, HSTS, and other security headers. HeaderGuard offers instant results without registration, detailed implementation guides for Nginx, Apache, Node.js, and WordPress, and security headers best practices tailored for 2026.

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