Free Tool by Sync Soft Solution

Security Headers Checker

Generate an HTTP Observatory-style report by scanning key security headers like HSTS, CSP, X-Frame-Options, Referrer-Policy, Permissions-Policy and more. Get a clear score + grade with practical fixes.

Accurate Redirect-Safe Scan ✅ GET-based scan ✅ Final response headers ✅ Multi-value headers
Tip: Cached for a few minutes Tip: Scan final HTTPS URL Tip: Start with HSTS + CSP
Security Headers & HTTP Observatory-Style Guide
Learn what security headers do, why your score matters, and how to fix missing headers the right way (without breaking your website).

What is a Security Headers Checker?

A Security Headers Checker scans your website’s HTTP response headers and evaluates protections that modern browsers use to prevent common attacks. Think of these headers as a browser security policy for your site: they define what scripts can run, whether your pages can be embedded inside frames, how referrer data is shared, and whether the browser should enforce HTTPS.

Our tool generates an HTTP Observatory-style report with a practical score + grade. It focuses on the headers that give the biggest security and trust benefits for real-world websites—including lead-gen sites, WordPress builds, eCommerce stores, and high-traffic service pages.

Graphic: Browser Security Layer
CSP blocks malicious scripts HSTS enforces HTTPS XFO / frame-ancestors stops clickjacking Security headers are a “browser policy” for your site.
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Why security headers matter

Website security is not only server-side. Many attacks happen inside the browser—through injected scripts, hostile frames, or unsafe third-party resources. Security headers help browsers enforce rules like “only load scripts from trusted sources” or “never allow framing.” This reduces the impact of XSS, clickjacking, credential theft flows, and trust issues that can hurt leads and sales.

For service websites and SEO landing pages, security also improves user trust. Visitors are more likely to fill forms and call when the browsing experience feels safe and consistent—especially on mobile devices and public networks.

XSS (Cross-site scripting)
A malicious script can steal sessions, inject spam links, redirect payments, or modify page content. CSP limits what can run.
Clickjacking
Attackers embed your site in an invisible frame to trick users into clicking dangerous UI. XFO/CSP frame-ancestors blocks it.
SSL stripping
Without HSTS, users can be forced onto HTTP before HTTPS. HSTS tells the browser to always use HTTPS.
Data leakage
Referrer-Policy reduces exposing internal paths/queries to third-party sites when users click outbound links.
Supply chain risk
Third-party scripts can be abused. CSP restricts where scripts, fonts, and connections can load from.
Browser feature abuse
Permissions-Policy disables access to features like camera/mic/geolocation when your site doesn’t need them.

Why many header scanners give false reports

Many tools produce false results because they do one of these:

  • They use HEAD requests: some servers return different headers for HEAD vs GET (or block HEAD entirely).
  • They don’t follow redirects correctly: they scan the first hop (HTTP) instead of the final HTTPS page.
  • They parse headers incorrectly: redirects can return multiple header blocks—wrong parsing picks the wrong block or mixes body content.
  • They treat optional headers as mandatory: COOP/COEP/CORP can break embeds, so many sites intentionally skip them.

This tool is designed to be redirect-safe, uses a GET-based scan, and captures the final response headers reliably.

HSTS: Strict-Transport-Security

HSTS tells the browser to always use HTTPS for your domain. It helps prevent downgrade attacks and ensures users don’t accidentally load insecure HTTP versions. 

Strict-Transport-Security: max-age=31536000; includeSubDomains; preload

Use preload only if all subdomains are HTTPS permanently.

CSP: Content-Security-Policy

CSP is the most important browser-side defense for many sites. It limits where scripts/styles/images/fonts can load from and where your pages can connect. If an attacker injects code, CSP can stop it from executing or calling malicious endpoints. 

Content-Security-Policy: default-src 'self'; base-uri 'self'; object-src 'none'; frame-ancestors 'self'; upgrade-insecure-requests

Start with Report-Only first on complex sites, then enforce gradually.

Clickjacking protection: X-Frame-Options / frame-ancestors

Clickjacking happens when your page is embedded inside a malicious frame. The attacker overlays fake UI and tricks users into clicking hidden buttons. Protect with X-Frame-Options or CSP frame-ancestors. 

X-Frame-Options: SAMEORIGIN

X-Content-Type-Options: nosniff

Prevents MIME sniffing—browsers won’t guess file types and accidentally treat content as executable scripts. 

X-Content-Type-Options: nosniff

Referrer-Policy

Controls how much referrer information is sent when users click outbound links. A safe modern default is: 

Referrer-Policy: strict-origin-when-cross-origin

Permissions-Policy

Limits access to browser features (camera, microphone, geolocation). If your site doesn’t use them—disable them. 

Permissions-Policy: geolocation=(), camera=(), microphone=()

Fix strategy (safe order)

  1. Add low-risk headers first: X-Content-Type-Options, Referrer-Policy, X-Frame-Options.
  2. Confirm HTTPS everywhere → enable HSTS.
  3. Implement CSP using Report-Only → enforce gradually.
  4. Rescan after each change using this tool.
Need help implementing CSP/HSTS?
Call 8750347699 or WhatsApp and we’ll implement security headers safely without breaking tracking and ads.

FAQ

Why is my grade still low after adding some headers?
The score is weighted. HSTS and CSP carry the most impact. Make sure HSTS includes max-age (on HTTPS) and CSP contains at least default-src or script-src.
Should I add COOP/COEP/CORP?
These are advanced headers and can break third-party embeds. Add them only if you understand cross-origin isolation and have tested in staging.
Can this tool check subdomains too?
This tool scans the URL you enter. If you want to check subdomains, scan each subdomain URL separately.
How often should I scan?
Scan after any CDN/server change, plugin update, or security hardening. For high-traffic websites, monthly audits are recommended.
Do security headers affect conversions?
Yes. Security hardening reduces browser warnings and builds trust—especially important for lead forms and checkout flows.

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