We’re going to assume that you are using the WordPress Classic Editor. The latest version of WordPress utilizes the new Gutenburg editor so be sure that you are using the classic editor before referring to this article. If you have upgraded to the latest version of WordPress and still want to use the classic editor, download and install the Classic Editor plugin.
Upload images to Media Library
The first step is to upload your images. To do this click on Media > Add New > Select Files. Navigate to your photos and select the photos you would like to upload.
If you are having trouble uploading images, see the Troubleshooting section below.
Create a Gallery page
The next step is to create a page for your Gallery. To create a page, select Pages > Add New.
If you or someone has already created a page for your gallery, skip to the next step.
Add your Gallery
Go to the page you created for your gallery. Click in the text area. Click the Add Media button above the tool bar. In the left navigation pane, click Create Gallery. Click the images you would like to add to the gallery. In the lower right-hand corner, click “Create a new gallery”. In the right-hand navigation pane under Gallery Settings, you can specify the number of columns for your images and the actual size of the gallery image. Thumbnail is the default size and is the typical size for a gallery image. You may also add a caption to each image. Link to “Attachment Page” is the default Link to setting.
Click the “Insert gallery” button. Now click the “Update” button in the right-hand menu to save your gallery page and you are done!
Edit your Gallery
If you need to edit your gallery page, simply click on the gallery you created while in the page editor. Be sure the Visual tab is selected not the Text tab so you can see your images. A box will pop up with two icons. Click the “X” icon if you wish to delete the gallery. Click the “pencil” icon to change the gallery settings. You can remove images, add images, add image captions, specify number of columns, reverse the image order and select to display images randomly.
Optional Plugins
When you click on a gallery image, it will open in a new page with the image title displayed. If no title has been specified for the image, the image file name will be used. A fancier option is to have the image open in a lightbox. This is easily achieved by installing a lightbox plugin such as Responsive Lightbox or Responsive Lightbox Pro.
WordPress does not do a very good job of organizing your images. To keep track of your image uploads, you may want to install a plugin called Enhanced Media Library. With this plugin you can create categories for your images, allowing you to tag images with a specific category which makes them easier to find when you need them.
Troubleshooting
One of the issues you may run into include trying to upload images that are too large. You may see a message that reads “[image name] exceeds the maximum upload size for this site”. In this case, you may need to compress your images.
Images uploaded to the Media Library should be compressed before uploading. Compression does not refer to the actual pixel dimensions of the image but rather to the file size of the image. Compression is a mathematical operation that is performed on an image file to reduce its size and yet retain image quality. There are many programs that you can use to accomplish this such as Adobe Photo Shop (if you enjoy purchasing expensive software) or Corel Paint Shop Pro (if you are on a more limited budget). There are also a few free browser-based image editors such as PIXLR at pixlr.com. If you don’t feel comfortable using this software or you just don’t have the time or inclination, you can install a plugin called Imsanity. Imsanity will automatically compress uploaded images. You can tell Imsanity how much compression you want to apply to the images. You can also specify the height and the width in pixels of the images to be uploaded.
Be sure that your file type is supported by WordPress. The most common image file types supported by WordPress are: JPG, JPEG, PNG, and GIF.
Summary
Though there may be some advantages to using a gallery plugin, you really don’t need a gallery plugin to create a WordPress gallery.
Optional plugins: Enhanced Media Library, Responsive Lightbox Pro, Imsanity