HTTP Security Headers Checker
Check all security-related HTTP headers for any URL and get an instant A-F security grade. Our HTTP security headers checker examines HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, and CORS headers, providing detailed analysis and actionable recommendations for each one. Fast, secure, browser-based, and completely free - no signup required.
Check all security-related HTTP headers for any URL. Get an A-F security grade based on the presence and configuration of HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, and CORS headers - all with detailed analysis and actionable recommendations.
Enter a URL to check its HTTP security headers (https:// is added automatically if missing)
Why Use Our HTTP Security Headers Checker?
Comprehensive Security Header Scan
Checks 7 critical security headers including HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, and CORS. Every header is analysed for presence, value correctness, and best practice compliance.
A-F Security Grading System
Each URL receives an easy-to-understand letter grade from A (excellent) to F (failing). The grading weights critical headers more heavily, so missing HSTS or CSP alone can drop you multiple grades. Instant visual feedback on your security posture.
Detailed Analysis & Recommendations
Every security header includes a plain-English analysis of its current configuration and specific, actionable recommendations for improvement. Expand any header to see the current value, what it means, and exactly how to fix it.
Browser-Based, Private & Free
All checks run directly from your browser using fetch requests - no server proxy, no data logging, no signup required. Your URLs and results never leave your device. 100% free with no usage limits.
Common Use Cases for HTTP Security Headers Checker
Website Security Audits
Run quick security header audits on any website to assess its security posture. Check if the site enforces HTTPS with HSTS, prevents XSS with CSP, protects against clickjacking with X-Frame-Options, and follows other security header best practices - all in seconds.
Pre-Deployment Security Checks
Before launching a new website or web application, verify that all security headers are properly configured. Our HTTP security headers checker helps catch missing headers early in the deployment pipeline, preventing security gaps from reaching production.
Compliance & Regulatory Audits
Security headers are increasingly required by compliance frameworks (PCI DSS, ISO 27001, SOC 2). Use the checker to document which headers are present, generate audit-ready reports, and track improvements over time for compliance evidence.
Security Incident Investigation
When investigating a security incident, check whether missing or misconfigured security headers contributed to the vulnerability. The detailed analysis for each header helps identify exactly what was missing and provides remediation steps.
Competitive Security Benchmarking
Compare your website's security header configuration against competitors or industry leaders like Google, GitHub, and Cloudflare. See what headers the best-in-class websites use and get actionable guidance to match their security posture.
Learning Web Security Best Practices
New to web security? Use the HTTP security headers checker as a learning tool. Each header includes a plain-English explanation of what it does, why it matters, and how to configure it correctly. Perfect for developers learning about web application security.
Understanding HTTP Security Headers
What Are HTTP Security Headers?
HTTP security headers are response headers that a web server sends to a browser to instruct it on how to behave regarding security. They act as a protection layer between your website and potential attacks like cross-site scripting (XSS), clickjacking, MIME-type sniffing, and protocol downgrade attacks. Unlike server-side security measures, security headers leverage the browser's own security mechanisms to protect users.
How Our HTTP Security Headers Checker Works
- Enter a URL - Type or paste the URL you want to check. The tool automatically adds https:// if no protocol is specified.
- Fetch & Analyse - Your browser sends a HEAD request to the URL, retrieving only the response headers without downloading the full page body. All 7 critical security headers are examined.
- Grade & Report - Each header is analysed for presence, value correctness, and best-practice compliance. An overall grade from A to F is calculated, with detailed analysis and actionable recommendations for every header.
What Security Headers Are Checked?
- Strict-Transport-Security (HSTS) - Enforces HTTPS connections and prevents SSL stripping attacks.
- Content-Security-Policy (CSP) - Controls which resources can be loaded, preventing XSS and data injection.
- X-Frame-Options - Prevents clickjacking by controlling iframe embedding.
- X-Content-Type-Options - Stops browsers from MIME-type sniffing, preventing content-type confusion attacks.
- Referrer-Policy - Controls what referrer information is sent with requests, protecting user privacy.
- Permissions-Policy - Restricts access to browser APIs like geolocation, camera, and microphone.
- Access-Control-Allow-Origin (CORS) - Controls cross-origin resource sharing to prevent unauthorised data access.
Privacy, Security & Availability
Your privacy is paramount. All checks are performed directly from your browser using the standard fetch API - your URLs are never sent to our servers, and no data is logged or stored. The HTTP security headers checker is completely free to use with no signup, no API keys, and no usage limits. Results are processed entirely in your browser and disappear when you close or refresh the page.
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Frequently Asked Questions About HTTP Security Headers Checker
HTTP security headers are response headers that a web server sends to a browser to enforce security policies. They include headers like Strict-Transport-Security (HSTS) which enforces HTTPS, Content-Security-Policy (CSP) which prevents XSS attacks, and X-Frame-Options which prevents clickjacking. These headers are a critical part of defence-in-depth for any modern website.
The grade is calculated based on the presence and configuration of 7 security headers. Critical headers (HSTS and CSP) are weighted more heavily. To get an A grade, all 7 security headers must be present and properly configured. A B grade means all critical headers are present but one or more recommended headers may be missing. An F grade means critical security headers are missing and immediate action is required.
Some servers block HEAD requests, require authentication, or have CORS restrictions that prevent browser-based header inspection. The website may also be behind a CDN or firewall that modifies or strips certain headers. Server downtime or network issues can also cause failures. If a URL consistently fails, try using a different protocol (http:// instead of https://) or check if the server requires a specific User-Agent header.
Strict-Transport-Security (HSTS) and Content-Security-Policy (CSP) are considered the most critical. HSTS forces HTTPS connections and protects against SSL stripping attacks. CSP is the most powerful defence against XSS attacks, controlling which scripts, styles, and other resources the browser is allowed to load. Both are weighted as critical in our grading system, and missing either one significantly impacts your security grade.
While the general HTTP Header Checker shows all response headers (including caching, content negotiation, and connection headers), the HTTP Security Headers Checker focuses exclusively on security-related headers. It provides a graded security score, detailed analysis of each security header's configuration, and specific actionable recommendations for improvement. Think of it as a dedicated security audit tool for HTTP headers.
Absolutely. All security header checks are performed directly from your browser using the standard fetch API. Your URLs and the results are never sent to any server - everything stays in your browser. We do not log, store, or process any data. No signup or account is required, ensuring your privacy is protected at all times.
The tool has a 15-second timeout for each URL check. If a server is slow to respond, the fetch may time out with a 'Request timed out' error. This typically indicates network issues, server load, or firewall restrictions. Try checking a different URL or the same URL later to see if the issue persists.
Currently, the tool checks one URL at a time. However, there is no usage limit - you can check as many URLs as you need, one after another. The clear button quickly resets the form for your next check. For bulk header checking across multiple URLs, we recommend using our general HTTP Header Checker or a dedicated security scanning tool.
Yes! The HTTP Security Headers Checker is completely free with no signup, no account, and no usage limits. Check the security headers of any URL as many times as you need. All processing happens locally in your browser, keeping your data private while saving our server costs - a win-win for everyone.