HTTP Header Checker
Analyze HTTP response headers for security vulnerabilities, performance issues, and server configuration insights.
Analyzing HTTP Headers...
Making request and analyzing server response headers.
Header Analysis Summary
| Header Name | Value | Category | Status |
|---|
Security Headers Analysis
Redirect Chain Analysis
Why HTTP Headers Matter for Security and SEO
HTTP headers are invisible directives sent by web servers that control how browsers and search engines interact with your website. They affect everything from security and privacy to performance and search engine crawling.
According to OWASP, proper HTTP headers can prevent over 70% of common web attacks, while Google has confirmed that security (HTTPS) and page speed (affected by cache headers) are ranking factors in search results.
Critical Security Headers Explained
1. Content-Security-Policy (CSP)
Purpose: Prevents Cross-Site Scripting (XSS) attacks by specifying which content sources are trusted.
Example: Content-Security-Policy: default-src 'self'; script-src 'self' https://trusted.cdn.com
Impact: Critical for preventing data theft and session hijacking. Missing CSP is a severe security risk.
2. Strict-Transport-Security (HSTS)
Purpose: Forces browsers to use HTTPS only, preventing SSL stripping attacks.
Example: Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
Impact: Essential for all HTTPS sites. Protects against man-in-the-middle attacks.
3. X-Frame-Options
Purpose: Prevents clickjacking by controlling whether your site can be framed.
Example: X-Frame-Options: SAMEORIGIN or X-Frame-Options: DENY
Impact: Protects users from interface manipulation attacks.
4. X-Content-Type-Options
Purpose: Prevents MIME type sniffing, which can lead to XSS attacks.
Example: X-Content-Type-Options: nosniff
Impact: Simple but effective protection against content-type based attacks.
5. Referrer-Policy
Purpose: Controls how much referrer information is sent with requests.
Example: Referrer-Policy: strict-origin-when-cross-origin
Impact: Protects user privacy and prevents sensitive URL information leakage.
Performance & SEO Headers
Cache-Control
Purpose: Controls caching behavior in browsers and CDNs.
SEO Impact: Proper caching improves page load times, which is a Google ranking factor. Static resources should have long cache times (e.g., max-age=31536000), while dynamic content should use appropriate cache directives.
X-Robots-Tag
Purpose: Provides crawling directives to search engines at the HTTP level.
Example: X-Robots-Tag: noindex, nofollow
SEO Impact: Can override meta robots tags. Useful for controlling indexing of non-HTML files (PDFs, images).
Link Header (for Preload/Preconnect)
Purpose: Specifies resources to preload or connections to pre-establish.
Example: Link: </style.css>; rel=preload; as=style
SEO Impact: Improves perceived load speed, which affects user experience and rankings.
Common Header Issues and Their Impact
| Issue | Impact | Severity |
|---|---|---|
| Missing HSTS header | SSL stripping attacks possible | Critical |
| No CSP header | XSS vulnerabilities | Critical |
| Missing X-Frame-Options | Clickjacking risk | High |
| Server header reveals version | Information disclosure | Medium |
| Poor Cache-Control settings | Slow page loads, poor UX | Medium |
| Missing X-Content-Type-Options | MIME sniffing possible | Low |
How to Fix Common Header Issues
- For Apache servers: Add directives to .htaccess file:
Header set Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" Header set X-Frame-Options "SAMEORIGIN" Header set X-Content-Type-Options "nosniff" Header set Referrer-Policy "strict-origin-when-cross-origin"
- For Nginx: Add to server block in nginx.conf:
add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always; add_header X-Frame-Options "SAMEORIGIN" always; add_header X-Content-Type-Options "nosniff" always; add_header Referrer-Policy "strict-origin-when-cross-origin" always;
- For Cloudflare: Use Transform Rules or Page Rules to add headers
- For WordPress: Use security plugins like Security Headers or add to functions.php
- For custom applications: Set headers in your application code or middleware
Frequently Asked Questions (FAQ)
Can HTTP headers affect my website's search rankings?
Yes, indirectly. While Google doesn't directly rank based on security headers, they affect:
- Page speed: Cache-Control and other performance headers affect load times
- Security: HTTPS (enforced by HSTS) is a ranking signal
- Crawling: X-Robots-Tag controls search engine access
- User experience: Security warnings for missing headers can increase bounce rates
Should I hide the Server header that shows my server version?
Yes, it's a security best practice. Revealing server versions (like "Apache/2.4.41" or "nginx/1.18.0") gives attackers information about potential vulnerabilities. You should either remove or obfuscate the Server header. However, note that sophisticated attackers can often fingerprint servers through other means.
What's the difference between X-Frame-Options and Content-Security-Policy frame-ancestors?
X-Frame-Options is an older header with limited options (DENY, SAMEORIGIN, ALLOW-FROM). Content-Security-Policy's frame-ancestors directive is more flexible and modern, allowing you to specify multiple origins. CSP is gradually replacing X-Frame-Options. For maximum compatibility, you can use both, but CSP frame-ancestors takes precedence in browsers that support it.
How do I test if my security headers are working correctly?
Use multiple methods:
- This HTTP Header Checker tool
- Browser Developer Tools (Network tab)
- Command line:
curl -I https://yourdomain.com - Security scanners: SecurityHeaders.com, Mozilla Observatory
- Google Search Console Security Issues report