As the expression goes, “Don’t judge a book by its cover.” Well, people still do, and the same goes for featured images on your WordPress website. When paired with an engaging title, the right featured image captures visitors' attention. When they click your article, the featured image is one of the first things visitors see and may affect their perception of your content before they even start reading.
All this is to say that you need to get your WordPress featured image sizing right. In this guide, I’ll explain how to adjust the size of your featured images to best suit your pages and posts. But first, let’s discuss the purpose of featured images and how to set them on your WordPress site.
What is a featured image in WordPress?
A featured image visually represents a post or page on your WordPress website. Featured images usually appear on your website at the top of posts. They also appear when you share your posts outside of your WordPress site, like on social media or news websites. The purpose of the featured image is to draw readers to your content and signal what your posts are about and reinforce your site’s tone and branding.
In most cases, your active WordPress theme determines if and how featured images will be displayed on your site. Since featured images are so important, most reputable WordPress themes have them enabled.
Still, there’s a good chance that your featured images will look different across themes, so It’s important to ensure the files you intend to use as featured images are optimized.
Where a featured image might appear on your site depends on your theme, but you can typically expect to see your image appear in at least these three places:
- Anywhere on your website that links to the blog post associated with the featured image, such as your homepage, a search results page, or a recommended posts area. In this context, the image serves as the “thumbnail” for the piece.
- At or near the top of your posts or pages. The exact positioning will vary by theme.
- When you share your posts on other online channels, namely social media sites like Twitter or LinkedIn. If you set a featured image, these platforms will make it the thumbnail by default.
Here’s a basic example of featured images on a WordPress homepage using the Fortune theme:
How to Set a Featured Image in WordPress
To add a unique custom featured image to a post or page on your WordPress site:
1. Open the editor for the post or page.
2. Click the gear icon in the top right corner to open the settings panel.
3. In the settings panel under the Document tab, select Featured image > Set featured image.
4. Upload your featured image or select one from your media library.
5. In the Alt Text field, add alternative text that describes your featured image. Informative, accurate alt text is a key step to optimizing your WordPress site’s SEO.
6. Add a Title, Caption, and/or Description if desired.
7. Click Set featured image.
8. Back in the editor, click Preview to see your featured image in context.
You can replace or remove your featured image in settings under Document > Featured image.
WordPress Featured Image Size
A good starting point for your WordPress featured image size is 1200 x 628 pixels. These dimensions tend to work well across WordPress themes and page layouts, and also look good when shared on social media feeds.
Here’s what a 1200-by-628-pixel featured image looks like in a post with the Twenty Twenty-One Theme:
However, the best featured image size for your specific site might vary depending on your theme layout and your personal preference. For example, you may prefer a different aspect ratio (1200 x 628 translates to about a 16:8.4 aspect ratio). Or, you may want to tailor your featured image dimensions to look best on the social media site you share to most often.
Also, your theme’s specific layout might default to WordPress’ featured image dimensions or have their own dimensions. In most cases it’s possible to change your featured image size to your liking.
How to Change Featured Image Size in WordPress
Altering the look of your featured images is a major change to the appearance of your site, so let’s take the process set-by-step. We also recommend testing these modifications on a WordPress staging site to hide any formatting errors from the public until you take your changes live.
1. Understand WordPress image sizes.
In order to change the size of featured images on pages and posts, it’s important to first get a handle on WordPress default image sizing.
When you add an image to your media library, WordPress automatically makes three copies of the original image in three dimensions:
- Thumbnail size, cropped to 150x150 pixels by default.
- Medium size, with a maximum width/height of 300 pixels by default.
- Large size, with a maximum width/height of 1024 pixels by default.
These copies are created so the image can be used in different sections of your website without needing to resize the original image each time, which would decrease page performance. Imagine uploading a 2000 x 1200 pixel image as a featured image. This relatively high resolution makes sense when placing the image full-width on the top of a post. However, it would be impractical to squeeze this large image into a smaller area, like an image gallery. That's why WordPress makes smaller versions of the same file.
While WordPress’ image resizing is often helpful, the default sizes won’t work perfectly for featured images on every WordPress site. For instance, your WordPress theme might require larger or smaller dimensions for your featured images in different places on your site. In this case, the theme might automatically overwrite the default WordPress image sizes.
Alternatively, you might want to adjust these dimensions manually. This is easy to do in WordPress — let's learn how.
2. Change your featured image dimensions.
To change the sizes of your featured image, the first place you should look is your theme. Many themes add their own featured image dimensions to be used in place of the WordPress defaults. Check the options under the Appearance tab in the left side panel, and look for options to toggle the featured image size within your specific theme.
If no option exists in your theme settings, you can change the default featured image size in your WordPress settings.
To change the default images sizes in WordPress:
1. From the WordPress dashboard, select Settings > Media.
2. In the number fields next to Thumbnail size, input the desired dimensions for your featured images. (WordPress uses the terms “thumbnail” and “featured image” interchangeably.)
3. Click Save Changes.
3. Reformat your old featured images
Default image sizes are only applied when you upload images to WordPress, so the new dimensions will only apply to images uploaded after you change these settings. To resize your old images to the new specifications, re-upload them manually or use the Regenerate Thumbnails WordPress plugin to handle this for you.
When uploading new featured images from now on, size them at least as large as the featured image dimensions you’ve set to avoid blurry or warped photos.
Also, consider cropping featured images to the WordPress thumbnail dimensions before uploading to avoid issues with auto-cropping. Some experimentation will probably be necessary here to achieve a good fit.
How to Optimize WordPress Featured Images for Search
You’ve got your featured image sizing sorted out, but we’re not done just yet. Featured images have the potential to attract not only readers but search engines too. You just need the right alternative text and title.
Alt text serves two purposes:
- It describes the image to those who might not be able to view it clearly, including readers with visual impairments and readers with slow internet connections.
- It helps search engines like Google list websites in results pages.
By adding clear alt text containing your relevant keywords, search engines might rank your content higher in search results.
For example, the alternative text in this blog post is “two people sitting on a couch and using a computer to adjust WordPress featured image size”. This description (1) tells the reader the contents of the image, and (2) includes important keywords for this article that signal its relevance to Google.
Similarly, putting relevant keywords in the featured image title also helps search engines index your pages. I’ve titled the featured image of this article “wordpress-featured-image-size” for this purpose.
Note that all non-decorative images on your website should have alternative text and descriptive titles, not just your featured images. To learn more about images and SEO, see our Marketer's Guide to Optimizing Images for Google Search.
Do your featured images size up?
For most WordPress websites, featured images are a no-brainer. They engage and inform your visitors, unify your brand, provide a professional look, boost SEO, and increase the overall value of your website for your leads and customers.
It might sound nit-picky, but the look, layout, and meta-details of your featured images matter a lot. A warped, blurry, or poorly-formatted image suggests you haven’t put enough work into what comes after it. How can your content be valuable if you don't nail the first photo?
Editor's note: This post was originally published in July 2020 and has been updated for comprehensiveness.
Originally published Jul 13, 2021 7:00:00 AM, updated July 13 2021