Social Preview Checker: Verify the Page and the Platform Cache

A social preview check inspects the metadata a page supplies for sharing. A local preview is an approximation: a social platform can fetch a different response, cache older metadata or choose its own rendering.

Inspect the final shared URL

Follow redirects and check the final page's Open Graph title, description, image and URL. Compare those values with the page's purpose and preferred canonical. Make image URLs absolute, publicly accessible and served with an appropriate response type. The social crawler must be able to fetch the page and image without your logged-in session.

Verify the image rather than its filename

Open the image URL directly. Check that it is the intended asset, not a missing-image page or a protected response. Use suitable dimensions and cropping for the platforms you actually use. A dimension recommendation is not a guarantee that every platform will display the entire image without cropping.

Worked example: a corrected title still shares incorrectly

Imagine a CMS title was corrected but an older headline continues to appear in a social post. First verify the live HTML and image response. Then use the relevant platform's supported debugging or refresh mechanism where available. Do not keep changing otherwise correct metadata to compensate for a cached preview. This hypothetical example separates publishing defects from cache behavior.

Check localized sharing

1. Share the intended language-specific URL.
2. Confirm that title, description and image text match that locale.
3. Check redirects without relying on a language cookie.
4. Avoid one generic og:url pointing every translated article to the homepage.
5. Retest after clearing or refreshing the platform preview through supported tools.

Use Social Preview Checker to catch missing values. It cannot promise an identical Facebook, Zalo or messaging-app rendering, and it does not publish or refresh a post on those services.

The Open Graph protocol documents the basic metadata fields. Platform-specific fetching and display rules can differ.