The link to your new service page goes into WhatsApp or LinkedIn, and the preview that appears shows your logo squashed into a corner, a random photo from the footer, or no picture at all. You change the image on the page, share it again, and the same wrong preview comes back.
Both problems have simple causes. The picture in a link preview is not chosen by the platform at random: it comes from a tag in your page’s code, usually written by your SEO plugin. Setting the social share image in WordPress properly takes a couple of minutes per page, and when an old preview refuses to change, it is almost always a cache on the platform’s side, which you can usually refresh.
Where the preview image comes from
When someone shares a link, the platform fetches the page and reads a small set of tags in the code called Open Graph tags. Facebook created the format, and LinkedIn, WhatsApp and many other apps read the same tags. The one that matters here is og:image, which gives the address of the picture to show. X (formerly Twitter) has its own similar tags, though it can fall back to the Open Graph ones when some of its own are missing.
WordPress itself does not add these tags. Your SEO plugin does. Rank Math and Yoast SEO both output Open Graph tags by default, so if you have either one active, you already have them. If you have no SEO plugin, the platform has to guess which picture to use, which explains the random footer image.
Social tags are one small part of the bigger list covered in our WordPress SEO basics guide. Everything else involved in looking after the site is in our guide to managing your WordPress site.
How the plugin chooses an image
SEO plugins pick the share image in roughly this order:
- An image you have set specifically for social sharing on that page.
- The page’s featured image, if it has one.
- A default image you have set for the whole site in the plugin’s settings.
Exact behaviour varies a little between plugins and versions, and some will also try an image from the page content. But the practical point is that the featured image does double duty. If your theme shows the featured image at the top of each post, see setting a featured image in WordPress for how that side works. This post is about the cases where you want the shared picture to be different, or where a page has no featured image at all.
A default social share image in WordPress
Do this first. It means any page without its own image still shares something sensible, such as your logo on a plain background or a good photo of your shop or team.
- Rank Math: the site-wide social image is in its Titles & Meta settings, in the global section, usually labelled as the OpenGraph thumbnail.
- Yoast SEO: look in the plugin’s site settings for the site image option, which is used when a page has no other image.
Choose an image that still makes sense when cropped and shown small. A logo alone on a wide white background often looks lost; a version of your logo placed on a coloured background in the right proportions usually looks better.
Set a custom Open Graph image for one page
For your important pages, such as the homepage, main service pages and anything you plan to share, set the image yourself.
- Open the page in the WordPress editor.
- Open your SEO plugin’s panel. In Rank Math, the Social tab has a Facebook section (which covers Open Graph) and an X or Twitter section. In Yoast SEO, the Social section has the equivalent fields.
- Upload or choose the image. You can also set a share title and description here, which are shown under the picture in many apps. If you leave them empty, the plugin uses your SEO title and meta description, which our post on changing the SEO title and meta description covers.
- Update the page.
- Open the page on the front end, view the source and search for “og:image”. You should see one line with the address of the image you chose.
If there are two og:image lines from different sources, another plugin or your theme is also writing social tags. Turn off the duplicate in that plugin’s settings, so only one source is in charge.
What size the picture should be
There is no single size every platform agrees on, and each one crops differently, but a wide, horizontal image around 1200 pixels across and 630 pixels high, a shape of roughly 1.91 to 1, is the size most commonly recommended for Facebook and LinkedIn link previews. It also works reasonably on X’s large card.
A few practical points matter more than the exact pixels:
- Keep the important part in the middle. Some apps show a square crop, especially in small previews on phones. Text or faces near the edges can be cut off.
- Use little or no text on the image. Your title already appears under the picture. Text in the image becomes unreadable at small sizes.
- Save it as JPEG or PNG. These are understood everywhere. Some apps handle newer formats less reliably in previews.
- Keep the file size reasonable. A very large file may be skipped by some platforms. Our free image compressor reduces the size without visible loss.
When the old preview will not go away
Platforms keep a copy of each link’s preview so they do not have to fetch your page every time it is shared. After you change the image, they keep showing the old one until their copy expires or you ask them to fetch it again.
- Facebook: use the Sharing Debugger on Meta’s developer site. Paste your page address and use the option to scrape it again. The tool also shows exactly which tags it found, which is useful for diagnosing problems.
- LinkedIn: use LinkedIn’s Post Inspector. Inspecting the address makes LinkedIn read the page again.
- WhatsApp: there is no public refresh tool. A common workaround when sharing is to add a harmless query to the end of the link, such as ?v=2, which makes it look like a new address. The old cached version eventually expires on its own.
Also clear your own site’s cache after changing the image. If your caching plugin or host is still serving the old page, the platforms will fetch the old tags.
If no image appears at all
- Check the og:image address opens in a browser. A typo, a deleted image or an http address on an https site can all break it.
- Check the image is not too small. Very small images may be shown as a tiny thumbnail or ignored.
- Check that a security plugin, firewall or CDN is not blocking the platform’s crawler. Facebook’s debugger shows an error if it cannot reach the page.
- Check the page is published and public. Drafts, password-protected pages and maintenance mode all hide the tags from platforms.
Frequently asked questions
Can I set a share image without an SEO plugin?
Yes. A small plugin that only adds Open Graph tags will do it, and some themes add the tags themselves. If you later install an SEO plugin, turn off the other source so the page carries only one set of tags. Check the page source afterwards for a single og:image line.
Can I use a different image for Facebook and for X?
Yes. Both main SEO plugins have separate fields for Facebook and for X in their social settings. Most owners use the same picture for both, but you can choose a different crop for X if its large card shows your image awkwardly.
Why does my homepage share the wrong image even though I set one?
The homepage sometimes has its own settings in the SEO plugin, separate from the page used as the front page, depending on how your site is set up. Check both places. Then refresh the platform’s cache with its debugging tool, because the old preview may simply still be stored.
Do I need to set a share image on every blog post?
Not if each post has a good featured image, because the plugin will use it. Set a custom image only for pages you will actively promote, or where the featured image is a poor fit for a wide preview. The site-wide default covers everything else.
Previews that stay wrong after all of this usually mean two sources are writing tags, or a cache somewhere is serving an old copy of the page. Our WordPress support team can work out which part of the site is responsible and set it right.
Next in this series: SEO Checklist Before Publishing a WordPress Page
