Your blog page shows a row of grey boxes where pictures should be, or a link you shared on LinkedIn appeared with your logo squashed into a corner. In both cases the post was missing the same thing: a featured image. It is one small setting, but your theme, your blog lists and your social previews all lean on it.
Below are the steps to set a featured image in WordPress, a look at where your theme will actually put it, and the shape and size that cause the fewest surprises. If you have set one and it refuses to show, that is a different problem, covered in our post on a featured image that is not showing.
What a featured image is for
A featured image is a single picture you choose to represent a post or page. You do not place it in the content. You attach it in the editor’s sidebar, and then the theme decides where to use it. Typical places are:
- at the top of the single post, above or behind the title;
- as the thumbnail beside each post on your blog page, category pages and search results;
- in “related posts” or “latest posts” sections, including the Latest Posts block;
- as the preview picture when someone shares the link, if your SEO plugin passes it on.
Some themes use it on pages too, as a banner. Others ignore it on pages entirely. That variation is why two sites can treat the same setting very differently, and why it pays to look at your own theme before deciding on sizes.
How to set a featured image in WordPress
- Open the post (or page) in the editor.
- Make sure the settings sidebar is open, using the settings icon at the top right, and select the Post (or Page) tab rather than the Block tab.
- Find the Featured image panel and click Set featured image.
- Choose an image from the Media Library, or switch to the upload tab and add a new one.
- Check the Alternative Text on the right while you are there.
- Click the Set featured image button at the bottom of the window.
- Save, update or publish the post.
To change it later, click the image in that panel to choose another, or use the remove option to clear it. The file stays in the Library either way.
On a site using the Classic Editor plugin, the same thing lives in a Featured image box in the right-hand column, with a “Set featured image” link.
If the panel is not there
Two common reasons. The panel may be switched off in the editor preferences: open the three-dot menu at the top right, go to Preferences, and look for Featured image in the panels section. Or your theme does not support featured images for that content type, which happens most often with pages. The second needs a theme setting or a small code change, not anything you can switch on from the post screen.
Where it shows depends on your theme
Once you have set one, open the post on the live site, then your blog page, and see what the theme did. Here the two kinds of theme part ways.
A block theme, such as the recent default themes, places the featured image with a Post Featured Image block inside the templates. Go to Appearance → Editor → Templates, open the Single Posts template or the Blog Home template, and click the image area. Its settings let you set an aspect ratio, a height, whether it links to the post, and an overlay. Removing that block from the Single template stops featured images showing on posts, while the setting itself remains.
Classic themes build this in code. Many offer choices under Appearance → Customize, often in a section for blog or post layout, such as hiding the image on single posts or changing the thumbnail shape on the blog page. What is available depends on your theme, so look before assuming you need a developer.
Page builders such as Elementor show the featured image only where a template or widget asks for it, for example a Featured Image widget in a single-post template.
These different places, and how they relate to images inside the content, are part of our guide to images and media in a WordPress site.
Featured image size and shape
There is no single correct featured image size, because each theme crops it differently. A few principles keep you safe across most themes and when links are shared:
- Use a wide shape. A wide image, roughly twice as wide as it is tall, suits most blog layouts and social previews. Square and portrait images are often cropped hard.
- Aim for around 1200 pixels wide. That is large enough for a full-width header on most themes and for social previews, without being heavy. Compress it before uploading.
- Keep the subject in the middle. Different parts of the site may crop the edges differently. A face at the far left may vanish in the blog list.
- Avoid text in the picture. Thumbnails shrink it to unreadable, and crops cut it. Put the words in the post title instead.
- Be consistent. Using the same shape for every post makes the blog page look ordered rather than jumbled.
To see exactly what your theme does, check the theme’s documentation for a recommended size, or look at the image on the blog page with your browser’s inspect tool to see which size WordPress is loading. The deeper story of image sizes and regenerating them belongs to our post on WordPress images that come out blurry or cropped.
Featured images and social sharing
When someone shares your post, Facebook, LinkedIn, WhatsApp and others look for an Open Graph image tag in the page. WordPress itself does not add one. SEO plugins such as Yoast SEO and Rank Math do, and they usually use the featured image unless you set a separate social image in the post’s SEO settings.
So a well-chosen featured image often doubles as your sharing preview. If you want a different picture on social media, or the preview shows an old image after you changed it, our guide to the social share image in WordPress explains the separate setting and how to refresh the cached preview.
Mistakes worth avoiding
- Adding the same photo as featured image and as the first block. Many themes then show it twice at the top of the post. Pick one.
- Using your logo on every post. The blog page becomes a wall of identical logos, and it tells readers nothing about each post.
- Leaving old posts without one. Lists that mix posts with and without images look broken. Fill the gaps when you have a spare half hour.
- Forgetting alt text. Themes take the featured image’s alt text from the Media Library entry, not from the post.
Featured images sit in the media section of our WordPress site owner’s handbook, next to the guides on settings, menus and the editor.
Frequently asked questions
Can I set a default featured image for posts that do not have one?
Not in WordPress itself. Some themes have an option for a fallback image, and small plugins exist that let you choose one default image for any post missing its own. SEO plugins can also set a default social sharing image. A real image chosen for each post is still better, because readers can tell posts apart.
What happens to my featured images if I change theme?
They stay attached to each post, because the setting is saved with the post rather than with the theme. The new theme decides where they appear and at what shape, so check the blog page and a few posts after switching. Older images may need their sizes regenerated with a plugin to suit the new theme’s crops.
Can I use a video as a featured image?
Not with core WordPress, which only accepts an image there. Some themes and plugins add a featured video option that replaces the image on the single post. For most business blogs, a still image as the featured image plus the video embedded in the content is simpler and works with every theme and sharing preview.
Why does my featured image look cropped on the blog page but fine on the post?
Your theme uses a different image size or shape for each place. The blog list often uses a smaller, fixed-shape crop to keep the grid even, while the single post shows a wider version. Keep the main subject near the centre of the picture, and check your theme’s settings for a thumbnail shape option.
Odd crops, doubled pictures and missing thumbnails on the blog page usually trace back to a theme setting or a template detail. Check the theme’s own options first; changing how the theme crops and places these images beyond that falls under our theme customization work.
Next in this series: How to Add a PDF to WordPress: Embed or Download
