The tags a link preview reads
The Open Graph protocol defines four required properties for every page, plus optional ones that most previews use. These describe what your page supplies; they do not control how a given app displays it or when it refreshes a stored copy. [1]
| Property | Required? | What it holds | What goes wrong |
|---|---|---|---|
| og:title | Required | The title as it should appear | Old title left by a template |
| og:type | Required | The type of object, such as website or article | Missing entirely |
| og:image | Required | URL of the image that represents the page | Points to an old logo or a broken file |
| og:url | Required | The canonical URL used as the page's permanent ID | Preview or staging address |
| og:description | Optional | A one to two sentence description | Generic site description on every page |
| og:site_name | Optional | The name of the overall site | Missing or inconsistent |
| og:image:alt | Optional, but expected with an image | A description of what is in the image, not a caption | Missing |
| og:image:width and og:image:height | Optional | Image size in pixels | Wrong values after a re-crop |
Inspect what the published page contains
Open the live page source and find the meta tags in the head. MDN describes the meta element as carrying metadata that other elements cannot, with name and content used together as name-value pairs; Open Graph uses the same element with a property attribute. Compare each value with the article actually on the page, and look at the generated output, not only the builder's settings form. [2]
Look for duplicate or conflicting tags from a template, plugin or old custom-code block. Check that og:url is the permanent public address, not a preview domain.
Worked example: correct article, wrong image
Hypothetical: the page /guide/ shows the new title, but og:image still points to /media/old-logo.png. The old logo loads fine. That is a mapping mistake in the page, not a problem with the app. Update the image setting for that page and check the generated source again.
Second case: og:image points to /media/guide-card.png, which returns an HTML error page instead of an image. The tag looks right but the file is wrong. Open the image URL on its own, check the response and look at the actual file. Rewriting the title would not fix this.
Choose an image that survives a small preview
- Use an image you own or have permission to publish.
- Avoid small text and screenshots containing private data.
- Keep the main subject readable when the image is shown small or cropped.
- Fill in og:image:alt with what the image shows; the Open Graph spec says a page with og:image should specify it.
- For a specific platform's size or crop rules, check that platform's current official instructions.
Retest and keep the scope honest
After fixing the page and image, use the destination app's preview or inspection tool if it has one; otherwise do one limited test share. Record the app and the time. Do not post repeated promotional links just to see whether a cached image changes.
Close the page defect when the generated tags and image are correct. Close the app observation only when that app shows the intended preview. If an app keeps an old preview and does not document how it refreshes, say so rather than promising a date. This guide is based on the Open Graph specification and MDN, not live tests of every social network.
Questions before you decide
Which Open Graph tags are required?
The Open Graph protocol lists four required properties: og:title, og:type, og:image and og:url. og:description and og:site_name are optional but commonly used.
Do I need alt text for the preview image?
The Open Graph protocol says that if a page specifies og:image it should specify og:image:alt, describing what is in the image rather than a caption.
Sources & verification
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- Open Graph protocol Accessed 29 Oct 2026
- MDN Web Docs: The meta HTML metadata element Accessed 29 Oct 2026
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