How to Regenerate Thumbnails in WordPress

Wait - you can regenerate your thumbnails in WordPress? Answer - yes you can. In this article, you’ll learn why you might need to do that, and how to regenerate thumbnails in WordPress.

A thumbnail is a smaller version of an image. This image might be necessary for the website to load faster. However, in WordPress, it could also mean resizing images in general to have a specific size.

In the general web community, these images are great for featured images, like for ecommerce shopping catalogs. You could sell books, and have a thumbnail image represent the listing. You could even use a thumbnail image to represent an article.

Here are a few reasons why you need to regenerate thumbnails in WordPress.

• Resize post or page’s featured image
• Resize product image
• Reduce overall image load
• Fit image to work with theme’s preferred image dimensions
• Generate images that are smaller and look best in smaller devices

Resize post or page’s featured image

Your posts may need a specific thumbnail size, other than the default 150x150 that WordPress offers. While you can adjust that size, you might want to keep that size and use a regenerate thumbnail related plugin to create new size images.

Resize product image

If you run an ecommerce store, your store’s product catalog may have different images from your post and page thumbnails.

Reduce overall image load

Having a fast loading WordPress site is important. A smaller image does load faster. Just make sure to optimize your images so while they may be smaller, they are at their best loading speed.

Fit image to work with theme’s preferred image dimensions

Every WordPress theme is different, and requires different image sizes. These images could be to complement specific design areas of your website, content images, and more.

It’s important to note, that instead of manually cropping or resizing, or using the image edit tool in the WordPress Media Library, a regenerated thumbnail plugin can help reduce that time, so you can use your time for creating more content and promoting it.

Additionally, if your WordPress site has gone through a new theme change, your new theme may not have the same exact recommended image sizes. You will want to regenerate the image sizes or even crop to fit the new dimensions.

Generate images that are smaller and look best in smaller devices

In regenerating smaller versions of your images, you can also use CSS to help make your site look more responsive in smaller devices, like tablets and smartphones. While you may have optimized your images, in most cases, you’ve probably optimized them for desktop users. You will want to also consider your mobile users so the website loads just as fast for them.

To regenerate thumbnails, you’ll be using the ReGenerate Thumbnails Advanced plugin. Please note, that you could also do this with the older Regenerate Thumbnails by another developer, but the plugin hasn’t been updated in 2 years. The reason that the ReGenerate Thumbnails Advanced plugin is being used in this article, is to avoid plugins that may or may not be up-to-date in code.

1. Find out what sizes your theme requires
2. Install and activate ReGenerate Thumbnails Advanced
3. Add new image sizes if necessary
4. Regenerate thumbnails in WordPress

1. Find out what sizes your theme requires

WordPress resizes for default images, but if you have images for specific sizes that need resizing, your theme may indicate that.

You can see your default media size settings under Settings, then Media, in your WordPress admin.

To see what your theme uses for image sizes, they may be coded into the theme, and the Regenerate Thumbnails Advanced plugin may automatically recognize them so you don’t need to add any new sizes, or look into the theme’s code to find them.

In the case of Regenerate Thumbnails Advance, you can see a list of what size images they found by going to Tools, and then Regenerate Thumbnails in your WordPress admin menu.

2. Install and activate Regenerate Thumbnails Advanced

Under your Plugins menu in your WordPress admin, click Add New, and search for “Regenerate Thumbnails Advanced”. You’ll need to click the button to install, and then again to activate the plugin.

3. Add new image sizes if necessary

If there is a specific image size you want to add, for whatever reason, you can do so with the Regenerate Thumbnails Advanced plugin.

Make sure to give the new image size a name, as well as give it a specific width and height. In most cases, you don’t want to crop the image, so make sure to select “No cropping”. The plugin automatically adds the new image size to your list of images to possibly resize.

4. Regenerate thumbnails in WordPress

Make sure to only select the image sizes that you want to resize. If you have an older and larger website, you might want to only select one type of image size at a time, in order to not overload your website’s resources, and bring the site down.

In the case of Regenerate Thumbnails Advanced, you can select how far back you’d like to resize images. You can find that under the dropdown labeled Regenerate Period.

Once you’re satisfied with the settings and images selected, you can scroll down and save settings. Once you’ve saved the settings, the Regenerate button will turn blue. This means you can now regenerate thumbnails in WordPress. The process may take a few minutes, depending on how many images need to be resized.

Please note that if you’re not an advanced user, before you save your settings for Regenerate Thumbnails Advanced, do not select deleting old sizes. You might accidentally delete something you need, and then somewhere on your website, there may be an image that no longer loads correctly.

Bet you didn’t know about needing to occasionally generate thumbnails in WordPress, right? Well, now you know the reasons why and how to do it. Give the Regenerate Thumbnails plugin a shot. Hopefully your thumbnails and other image sizes look right with the theme you’re currently using.