joerns

<ul>
<li>Adds <code>Content-Security-Policy: upgrade-insecure-requests</code> header if on HTTPS</li>
<li>Redirects to HTTPS if not on HTTPS and the browser sends <code>HTTP_UPGRADE_INSECURE_REQUESTS</code> header.</li>
</ul>
This is a simple, no-config plugin with focus on short, high quality code.

HTTPS Tool

Adds Content-Security-Policy: upgrade-insecure-requests header if on HTTPS. Redirects to HTTPS if not on HTTPS and the browser sends HTTP_UPGRADE_INSE …

cubecolour

A simple and lightweight plugin to indicate external http and https links in posts, pages and custom content by appending a small diagonal arrow icon to the link.
No configuration is required just install and activate.

Indicate External Links

Very reliable has survived many Wp updates and just keeps working.

This plugin just keeps on working

Indicates external links in post, page and custom content.

HTTPS Tool vs Indicate External Links