dath

With the dGal plugin you can simply create galleries. Just upload your images, add the dGal Shortcode to your posts or pages and the gallery will appear.
Mit dem dGal Plugin kannst du ganz einfach Galerien erstellen. Einfach deine Bilder hochladen, den dGal Shortcode deinem Eintrag oder deiner Seite hinzufügen und schon ist deine Galerie fertig.
Notice 
A new version of this plugin is now available as <a href="https://wordpress.org/extend/plugins/simplegal/" rel="ugc">SimpleGal</a>.

dGal

Create an Image-Gallery in 5 simple Steps (with Lightbox-Support!) | This plugin is now available in a new version as SimpleGal.

Noor Alam

<a href="https://noorsplugin.com/wordpress-colorbox-plugin/" rel="nofollow ugc">WP Colorbox</a> plugin is a simple lightbox tool for WordPress. It allows users to pop up content in lightbox using the popular jQuery ColorBox library. They can also view the larger version of a particular media file without leaving the page.
<iframe loading="lazy" title="WordPress Colorbox Plugin -- A jQuery Lightbox Plugin for WordPress" width="750" height="422" src="https://www.youtube.com/embed/2osxJcPTS1E?feature=oembed" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
<h4>Features</h4>
<ul>
<li>Beautiful lightbox popup style</li>
<li>Flexiblity of creating your own lightbox link</li>
<li>Pop up custom/HTML content in lightbox</li>
<li>Trigger lightbox from either a text/image link</li>
<li>Add lightbox to a YouTube or Vimeo video link</li>
<li>Enable lightbox functionality on your site which supports modern browsers</li>
<li>Use a simple shortcode to pop up a media file in lightbox</li>
<li>Apply lightbox effect on images inserted into WordPress post/page</li>
<li>Open external page in lightbox using iframe</li>
<li>Responsive lightbox popup which works on mobile devices. Also it fits perfectly on smaller screens.</li>
</ul>
<h4>How to Use WP Colorbox</h4>
Pop up image in lightbox
Create a new post/page and use the following shortcode to create a text/image link which will trigger lightbox once clicked:
<pre><code>[wp_colorbox_media url="https://example.com/wp-content/uploads/images/overlay.jpg" type="image" hyperlink="click here to pop up image"]
</code></pre>
here, url is the link to the media file that you wish to open in lightbox and hyperlink is the anchor text/image.
<pre><code>[wp_colorbox_media url="https://example.com/wp-content/uploads/images/overlay.jpg" type="image" hyperlink="http://example.com/wp-content/uploads/images/thumb.jpg"]
</code></pre>
Pop up YouTube video in lightbox
<pre><code>[wp_colorbox_media url="https://www.youtube.com/embed/nmp3Ra3Yj24" type="youtube" hyperlink="click here to pop up youtube video"]
</code></pre>
Pop up Vimeo video in lightbox
<pre><code>[wp_colorbox_media url="https://www.youtube.com/embed/1284237" type="vimeo" hyperlink="click here to pop up vimeo video"]
</code></pre>
Specify an Alternate Text for an Image
<pre><code>[wp_colorbox_media url="https://example.com/wp-content/uploads/images/overlay.jpg" title="overlay image" type="image" hyperlink="http://example.com/wp-content/uploads/images/thumb.jpg" alt="Thumbnail image description"]
</code></pre>
Apply Custom CSS
You can specify your own CSS class in the shortcode to customize a text/image link.
<pre><code>[wp_colorbox_media url="https://www.youtube.com/embed/nmp3Ra3Yj24" type="youtube" hyperlink="click here to pop up youtube video" class="custom_class"]
</code></pre>
Multiple CSS classes can be separated with a space. For example:
<pre><code>[wp_colorbox_media url="https://www.youtube.com/embed/nmp3Ra3Yj24" type="youtube" hyperlink="click here to pop up youtube video" class="custom_class custom_class2"]
</code></pre>
For detailed documentation please visit the <a href="https://noorsplugin.com/wordpress-colorbox-plugin/" rel="nofollow ugc">WordPress Colorbox</a> plugin page

WP Colorbox

Having to go to a website to see how to use this should be a huge no-no. Will not recommend this plugin to anyone.

Missing in-plugin documentation

View image, video (YouTube, Vimeo), page, inline HTML, custom content in lightbox. Add jQuery Colorbox lightbox effect to your WordPress site.

dGal vs WP Colorbox