When someone shares a web page on social media, the link preview often includes a title, description, and image. Open Graph is a set of page tags that tells social platforms what information to use for that preview. The tags sit in the page’s HTML head, where a platform’s crawler, a program that reads web pages, can find them.
On WordPress, an SEO plugin or another tool can add these tags. PressQueue also handles Open Graph images. Its social image can appear in a post shared through Buffer and in the preview when someone shares the post’s link.
What Open Graph tags tell social platforms
The Open Graph protocol describes how a web page can become a rich object in a social graph. Its specification lists four required properties:
| Property | What it tells the platform |
|---|---|
og:title |
The title to show for the page |
og:type |
The kind of object, such as a website |
og:image |
The image to use in the preview |
og:url |
The page’s canonical URL, used as its permanent identifier |
A canonical URL is the preferred address for a page when more than one URL could lead to the same content. For a standard web page, the protocol says to use website as its type.
Two other properties help shape the preview. og:description supplies a short description, and og:site_name identifies the site. Open Graph also supports image details such as alternative text, dimensions, and file type. The protocol recommends including alternative text when a page specifies an image.
These tags tell a crawler about the page, but each platform decides how to display the preview. Platforms use the information they receive, and their display rules vary.
How Open Graph tags affect a link preview
When a platform fetches a page, it reads the page information and uses it to build a preview. If the page has no Open Graph image, Facebook may select another image from the page, such as a logo or an ad, according to OpenGraphPlus’s Facebook tag reference. Setting og:image gives the page owner a direct way to specify the intended image.
The platform’s crawler must be able to reach the image. A Krumzi overview of Open Graph images recommends using a full image URL and notes that images behind a login or tags added only by JavaScript may not appear. Check that the image loads without signing in and that the tags appear in the HTML sent by the server.
A property can have multiple values on a page, including several og:image tags. The Open Graph specification says the first value in the page’s HTML takes priority when values conflict. If a preview shows the wrong image or title, inspect the page source for duplicate tags and check which one appears first.
Why an updated preview may still look old
Social platforms cache link previews. After changing a page’s title, description, or image, a platform may continue showing its saved version until it fetches the page again. Webflow’s instructions for social sharing describe using Meta’s debugger to request a fresh scrape and LinkedIn’s Post Inspector to request a re-scrape.
When a preview looks wrong, first check that the page has the intended tags and that anyone can access the image. Then use the platform’s tool to request a fresh scrape. This helps you tell whether the page’s metadata is wrong or the platform is showing an old cached preview.
How PressQueue handles Open Graph images
PressQueue is a free, open-source WordPress plugin that shares posts to social media through Buffer. It can set its generated social image as the post’s og:image and twitter:image. That image can then appear in the preview when someone shares the link. PressQueue works with Yoast SEO and Rank Math. It also supports The SEO Framework and Jetpack. Without an SEO plugin, it prints the tags itself.
To set it up:
- Download pressqueue.zip from the PressQueue download page. In WordPress, go to Plugins > Add Plugin > Upload Plugin and upload the ZIP.
- Paste a personal Buffer API key from your Buffer settings into PressQueue. PressQueue has no Buffer login button; it stores the key encrypted. Add or select the Buffer channels you want to use. New channels start switched off.
- In Settings > Social images, choose a background, font, text color, alignment, and site name. PressQueue draws an image using the post title and site name, with a wide shape for link previews. It creates the image when a post first needs one and redraws it when the title or style changes. It does not add the image to the WordPress Media Library.
- Choose how PressQueue handles link-preview tags: for every post, only for posts without their own image, or not at all. An image set for an individual post in an SEO plugin takes priority.
- Leave PressQueue in test mode while you check what it would share. When the post and channel settings are right, switch to Live. PressQueue’s rules control which posts go out and what message they carry. They also control timing, channels, and image.
PressQueue requires a WordPress site that supports plugin uploads, WordPress 6.8 or newer and PHP 8.1 or newer. You also need a Buffer account with social accounts added. It shares through Buffer to LinkedIn, X, Bluesky, Mastodon, Threads and Facebook. See the PressQueue documentation for setup details.