Toao.net

Sometimes, it’s not necessary to keep copies of full resolution images on your web server. But, when you solicit images from many sources, you may not be able to rely on users to size images to your specifications. Here’s a very simple plugin that removes the full resolution image and replaces it with an image resized to your preference.
The plugin makes no changes to your database and is written with just 17 lines of code.

Maximum Image Size

When extremely large images are uploaded to the Media Library, replace it with the Large size image, configured in Settings >> Media.

Archivarix

Archivarix External Images Importer will scan your posts and pages for external urls in src/srcset attribute for all img tags. Based on configured settings it can:
<ul>
<li>Download images from their external locations</li>
<li>Download images from Internet Archive (Wayback Machine)</li>
</ul>
You can choose what to do with images that could not be retrieved from external sources.
For further information and instructions please see <a href="https://archivarix.com/en/wordpress/" rel="nofollow ugc">Archivarix WP Plugin</a>

Archivarix External Images Importer

Works great!
I imported several posts into a site running WordPress 5.9.3 with Gutenberg and the Archivarix External Images Importer plugin imported the external images without any issues. I've tested a few other image importer plugins but none of them had the ability to scan a site and import from existing content like this one does.

Works with Gutenberg

Import external images in posts and pages from its original external sources or Web Archive if original source is unavailable.

Maximum Image Size vs Archivarix External Images Importer