Open Graph checker
Paste a public URL and we'll fetch its og:title, og:image, og:description, and Twitter card — exactly the way Slack, LinkedIn, and X will render it.
How to fix a preview that will not show up
- 01
Confirm the tags exist on the URL being shared
Not on the homepage, and not on the version behind a redirect - on the exact URL people paste. Previews are read from the final response, so a tag that only exists on the pre-redirect page might as well not exist.
- 02
Make the image absolutely addressable
og:image needs a full https URL that a stranger can fetch: no relative path, no login, no hotlink protection, no redirect. If you cannot open it in a private window, neither can the platform.
- 03
Give it the shape platforms expect
1200 by 630 pixels is the safe default, which is roughly 1.91:1. Stay under a few megabytes, use JPEG or PNG, and keep any text well inside the frame because different platforms crop different edges.
- 04
Re-scrape, do not just retry
Every network caches what it fetched the first time, including a failure. After a fix, use that platform's own debugger to force a fresh fetch - otherwise you are looking at a cached mistake and changing things that were never broken.
What each tag does
og:title and og:description
The headline and subtext of the card. They override the page title and meta description for sharing, which is useful: the phrasing that works in a search result is rarely the phrasing that works in a feed.
og:image
The one that gets noticed and the one that fails most often, almost always because it is unreachable rather than wrong. Set explicit width and height where you can - some platforms lay the card out before the image finishes downloading.
og:url
The canonical address of the thing being shared. It consolidates engagement counts when the same page circulates with different tracking parameters, so it should be the clean URL, not the tagged one.
twitter:card
Chooses between a small thumbnail and a large image. X falls back to the Open Graph tags for everything else, so this is usually the only twitter: tag worth adding.
Questions people ask about link previews
Why does my link show a blank preview?
Nine times out of ten the image is unreachable - a relative path, a private bucket, or a redirect the fetcher will not follow. The rest are pages that render their tags with JavaScript, which most preview fetchers never execute.
How do I clear a cached preview?
Through the platform's own debugger, because each one keeps its own cache: Facebook's Sharing Debugger, LinkedIn's Post Inspector, X's card validator. There is no universal purge, and simply resharing the link will not do it.
Do I need twitter: tags if I already have Open Graph tags?
Only twitter:card, and only if you want the large-image layout. Titles, descriptions and images all fall back to the og: equivalents.
Does the preview affect SEO?
Not directly - Open Graph tags are not ranking signals. They affect whether anyone clicks the link when it is shared, which is a different and often larger number.
Why does the same link look different on each platform?
Different crop ratios, different description lengths, and different caches with different ages. Design the image so it still reads when the edges are cut and the description is truncated.