Description
HeaderShield adds a conservative set of security headers that improve browser protection without breaking most sites. It also provides optional strict cross-origin protections for sites that are ready for them.
Default headers include:
- X-Frame-Options
- X-Content-Type-Options
- X-XSS-Protection (legacy)
- Referrer-Policy
- Permissions-Policy
- Content-Security-Policy (upgrade-insecure-requests)
- Strict-Transport-Security (HTTPS only)
Strict Mode can additionally enable COEP, COOP, and CORP for stronger isolation, but may break third‑party scripts or embeds. Use with care and test on staging first.
Source code for third-party assets
The admin UI uses SlimSelect for the multi-select dropdown. Human-readable source is included in the plugin:
- JavaScript:
assets/js/slimselect.js(minified build:assets/js/slimselect.min.js) - CSS:
assets/css/slimselect.css(minified build:assets/css/slimselect.min.css)
Upstream project: https://github.com/brianvoe/slim-select (MIT). This plugin does not use a custom build process; the included files are from the published release.
Installation
- Upload the
headershieldplugin folder to/wp-content/plugins/, or install via Plugins Add New and search for HeaderShield. - Activate the plugin through the Plugins menu in WordPress.
- Go to Security Headers in the admin sidebar to configure settings.
Optional: use as must-use plugin
You can also copy the main plugin file into /wp-content/mu-plugins/ so it is always active and cannot be disabled from the Plugins screen.
FAQ
-
Will this break my site?
-
The default headers are conservative and should be safe for most sites. Strict Mode may break embeds, analytics, fonts, or CDNs, so test on staging first.
-
Does this affect SEO?
-
No. These headers improve browser security and do not affect SEO.
Reviews
There are no reviews for this plugin.
Contributors & Developers
“HeaderShield” is open source software. The following people have contributed to this plugin.
Contributors
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Interested in development?
Browse the code, check out the SVN repository, or subscribe to the development log by RSS.
Changelog
1.0.14
- Initial public release.