Galleries are the best way to display a large number of images in your Posts.
The primary benefit of using a gallery is that you can display a large number of images at once. The trouble is, displaying many images at once requires them to be very small.
When a visitor clicks an image in one of your galleries, they’ll be presented with the lightbox above. This way they can view a larger version of the image, and navigate through the whole gallery at this size.
How to Setup the Jetpack Carousel Module
The first step is to install and activate the Jetpack plugin. Once activated, you’ll be asked to connect your site to WordPress.com. This will require creating a WordPress.com account if you don’t have one already.
Once you’re connected to WordPress.com, navigate to the Jetpack Settings menu. Locate the Carousel module, and click the “Activate” link that shows when you hover over it.
There’s no configuration necessary beyond activating the Carousel module. Your gallery images will now display in a lightbox when clicked.
Do I have to use Jetpack?
If you’re not excited about creating an account with yet another site, you can use the Gallery Carousel without Jetpack plugin instead.
It adds the same lightbox to your galleries that Jetpack does, but it doesn’t require the registration with WordPress.com, or all of the other functionality that comes with Jetpack.
Just activate the plugin, and it will start working. There’s no configuration or settings page.