Security headers summary for w3.org
This page validates the HTTP security headers returned by w3.org, scoring its protection against common web attacks.
Below you can review which headers w3.org sends, which are missing, and recommendations to harden the configuration.
What are HTTP security headers?
HTTP security headers are response headers that instruct the browser to apply protective policies, mitigating attacks such as XSS, clickjacking and content sniffing.
Key headers include Content-Security-Policy (CSP), Strict-Transport-Security (HSTS), X-Frame-Options, X-Content-Type-Options and Referrer-Policy.
How to interpret the headers of w3.org
A higher score means w3.org sends more of the recommended security headers with secure values. Missing headers are highlighted so you know what to add.
Focus first on CSP and HSTS for w3.org, as they provide the strongest protection against scripting and downgrade attacks.
Use cases
- Audit the security headers of w3.org before or after a deploy.
- Identify missing headers that increase attack risk on w3.org.
- Verify that w3.org enforces HTTPS with HSTS.
- Support hardening reports and security reviews for w3.org.
Frequently asked questions
Which security headers does w3.org use?
This page lists the HTTP security headers present on w3.org, such as CSP, HSTS, X-Frame-Options and X-Content-Type-Options, along with their values.
Does w3.org have a Content-Security-Policy?
The results show whether w3.org sends a Content-Security-Policy header and whether its value is considered secure.
Does w3.org enforce HTTPS with HSTS?
The Strict-Transport-Security section indicates whether w3.org forces HTTPS and for how long, including includeSubDomains and preload flags.
Why does w3.org have a low security score?
A low score means w3.org is missing important headers or sends insecure values. The missing-headers and recommendations sections explain how to improve it.
Is the security headers check for w3.org free?
Yes. The XploreNetHub Security Headers Validator is completely free, requires no sign-up and runs directly in your browser.
Related guides
- Security Headers Checklist — HSTS, CSP and HTTP headers before go-live.
- DNS and SSL Checklist — Steps and verification table before pointing a domain.