Jay Suthar

BoundaryGuard Headers enforces modern HTTP security headers to harden your WordPress site against XSS, clickjacking, mixed content, and cross-origin attacks.
Key Features:
<ul>
<li>Essential Protection: Adds X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy to reduce attack surface and prevent clickjacking.</li>
<li>HSTS (Strict Transport Security): Forces HTTPS connections to help prevent protocol downgrade and man-in-the-middle attacks.</li>
<li>Advanced Isolation (COOP/COEP): Enables Cross-Origin-Opener-Policy and Cross-Origin-Embedder-Policy to improve cross-origin isolation and mitigate certain side-channel attacks.</li>
<li>Content Security Policy (CSP): One of the strongest defenses against XSS. Includes a dashboard-based CSP builder with preset options to whitelist trusted sources for scripts, styles, images, and more.</li>
<li>CSP Report-Only Mode: Test your policy safely without blocking content.</li>
<li>Server Header Hardening: Removes or limits exposure of headers such as <code>X-Powered-By</code> and <code>Server</code>.</li>
<li>Lightweight and Fast: Uses PHP headers for broad server compatibility and minimal performance impact.</li>
<li>No <code>.htaccess</code> Editing Required: Works without modifying server configuration files.</li>
</ul>
Designed for developers and site owners who want stronger security without unnecessary complexity.
<h3>External Services</h3>
This plugin provides a Content Security Policy (CSP) builder. To assist users, it includes “Preset Buttons” that allow users to quickly add domain names to their own CSP whitelist.
This plugin DOES NOT connect to, load data from, or send data to these services automatically. The following third-party domains are referenced as presets within the admin dashboard for whitelisting purposes: 
* Google Analytics (www.google-analytics.com) – Used for tracking whitelisting. [Privacy: https://policies.google.com/privacy] 
* Google Tag Manager (www.googletagmanager.com) – Used for tag management. [Privacy: https://policies.google.com/privacy] 
* Stripe (js.stripe.com, api.stripe.com) – Used for payment processing. [Privacy: https://stripe.com/privacy] 
* Facebook (www.facebook.com, connect.facebook.net) – Used for social embeds. [Privacy: https://www.facebook.com/policy.php] 
* YouTube (www.youtube.com, i.ytimg.com) – Used for video embeds. [Privacy: https://policies.google.com/privacy] 
* Vimeo (player.vimeo.com) – Used for video embeds. [Privacy: https://vimeo.com/privacy] 
* Gravatar (secure.gravatar.com) – Used for user avatars. [Privacy: https://automattic.com/privacy/]

BoundaryGuard Headers

Automatically enforces essential HTTP security headers to protect your site from XSS, clickjacking, and protocol downgrade attacks.

Dimitar Ivanov

HTTP Headers gives your control over the http headers returned by your blog or website.
Headers supported by HTTP Headers includes:
<ul>
<li>Access-Control-Allow-Origin</li>
<li>Access-Control-Allow-Credentials</li>
<li>Access-Control-Max-Age</li>
<li>Access-Control-Allow-Methods</li>
<li>Access-Control-Allow-Headers</li>
<li>Access-Control-Expose-Headers</li>
<li>Age </li>
<li>Content-Security-Policy</li>
<li>Content-Security-Policy-Report-Only</li>
<li>Cache-Control</li>
<li>Clear-Site-Data</li>
<li>Connection</li>
<li>Content-Encoding</li>
<li>Content-Type</li>
<li>Cross-Origin-Embedder-Policy</li>
<li>Cross-Origin-Opener-Policy</li>
<li>Cross-Origin-Resource-Policy</li>
<li>Expect-CT</li>
<li>Expires</li>
<li>Feature-Policy</li>
<li>NEL</li>
<li>Permissions-Policy</li>
<li>Pragma</li>
<li>P3P</li>
<li>Referrer-Policy</li>
<li>Report-To</li>
<li>Strict-Transport-Security</li>
<li>Timing-Allow-Origin</li>
<li>Vary</li>
<li>WWW-Authenticate</li>
<li>X-Content-Type-Options</li>
<li>X-DNS-Prefetch-Control</li>
<li>X-Download-Options</li>
<li>X-Frame-Options</li>
<li>X-Permitted-Cross-Domain-Policies</li>
<li>X-Powered-By</li>
<li>X-Robots-Tag</li>
<li>X-UA-Compatible</li>
<li>X-XSS-Protection</li>
</ul>

HTTP Headers

Great plugin with a huge amount of settings. Despite the complexity of the setup, the developers have added comments with links to full help. It helps a lot that the comments are also translated into Russian.
After setting up the plugin, be sure to check both the functionality of the site and the speed indicators. Some settings may slow down the site loading speed.

Wonderful

HTTP Headers adds CORS & security HTTP headers to your website.

BoundaryGuard Headers vs HTTP Headers