eclev91

This will quickly tell your server has all the software installed to take advantage of WordPress 4.7’s built-in PDF thumbnail generation. Some plugins may shim the functionality in other ways. This test only concerns the native WordPress functionality.
From <a href="https://sternerstuffdesign.com" rel="nofollow ugc">Sterner Stuff Design</a>.
Tests: 
* ImageMagick 
* Imagick PECL Extension 
* GhostScript 
* Your WordPress Version

PDF Thumbnails Support Test

Determine if your server is missing software for WordPress 4.7's native PDF thumbnail generator.

Arno Welzel

This plugin integrates PhotoSwipe to WordPress. All linked images in a post or page will be displayed using PhotoSwipe, regardless if they are part of a gallery or single images.
More about the original version of PhotoSwipe see here: <a href="http://photoswipe.com" rel="nofollow ugc">http://photoswipe.com</a>
You can also display EXIF data from supported image types.
As of version 4.0.0 this plugin requires at least WordPress 5.3 and PHP 7.0. Older PHP version will cause problems. In this case you have to upgrade your PHP version or ask your hoster to do so. Please note that WordPress itself also recommends at least PHP 7.4 – see <a href="https://wordpress.org/about/requirements/" rel="ugc">https://wordpress.org/about/requirements/</a>.
Please keep in mind: not the visible thumbnail is relevant, but only the image link. Images should always be linked to the file and not to the attachment page. Since version 5.6.1 there is an option to fix attachment links which can be enabled if needed – however this may slow down your website since then all links on a page will be checked if they are attachment links.

Lightbox with PhotoSwipe

Amazing lightbox plugin

Integration of PhotoSwipe (http://photoswipe.com) for WordPress.

PDF Thumbnails Support Test vs Lightbox with PhotoSwipe