When you share a link on LinkedIn, Slack or X, the preview card that pops up (the title, image and blurb) doesn't come from the page's visible content. It comes from a set of meta tags in the page's head called Open Graph tags. Get them wrong, or leave them out, and the platform falls back to guessing: sometimes it picks a sensible image, sometimes it grabs the site's logo from an unrelated page, and sometimes the card shows up blank. A social card generator (Open Graph) builds those tags for you and lets you see the result before you publish, which matters because you rarely get a second chance at a first impression in someone's feed.
What Open Graph tags actually do
Open Graph is a protocol Facebook introduced and most other platforms adopted, whether or not they say so openly. It works by adding a handful of meta property="og:..." tags to a page's <head>, each one telling a sharing platform what to show: a title, a description, an image, a canonical URL, and sometimes a content type. X (formerly Twitter) reads a parallel set of twitter: tags, though it will fall back to Open Graph values if its own aren't present. Neither system reads your page's actual title tag or meta description by default, which is the root of most social card problems: people assume SEO metadata and social metadata are the same thing, and they aren't.
Why the preview matters more than you'd expect
A link shared without a proper card gets scrolled past. One with a clear title, a relevant image and a description that makes sense on its own gets a second look, particularly on platforms like LinkedIn where the image dominates the post. This isn't about vanity: for a business relying on shares, guest mentions or PR pickups to drive traffic, the social card is often the only piece of your content a prospective reader sees before deciding whether to click. A missing or broken image, or a title that's been truncated mid-word, quietly costs clicks that never show up in any analytics report as a specific loss.
The tags worth getting right
A handful of tags cover the overwhelming majority of cases. You don't need the full Open Graph specification, which includes options for video, audio and structured content types most sites will never use.
- og:title: the headline shown on the card. It can differ from your page's SEO title tag, and often should, since a title written for a search results page and one written to be read at a glance in a feed are doing different jobs.
- og:description: a short summary, typically cut off by most platforms well before 200 characters, so front-load the point.
- og:image: the picture shown on the card. This is the tag most often missing or pointing at the wrong file, and it's the one that does the most visual work.
- og:url: the canonical address for the page, which stops a shared link from splitting engagement across a tracked URL and the clean one.
- twitter:card: usually set to
summary_large_imageso X renders the same image prominently.
Common mistakes
Most broken social cards trace back to a small set of recurring errors, and they're worth checking specifically.
- No og:image at all, which leaves platforms to pick something themselves, often the first image on the page regardless of relevance.
- An image that's the wrong shape. Most platforms expect roughly a 1.91:1 ratio; a square product photo or a tall infographic gets cropped in ways you didn't intend.
- An image URL that isn't absolute. A relative path works fine in a browser but fails silently when a crawler on another domain tries to fetch it.
- Duplicate or conflicting tags left over from a page builder or plugin, where two different
og:titletags exist and the platform picks whichever one it parses first. - Caching. Facebook and LinkedIn both cache a page's Open Graph data the first time it's shared, so fixing the tags after a bad share doesn't update existing posts, and sometimes not new ones either until the cache expires or is manually refreshed through the platform's own debugging tool.
Image sizing in practice
A safe working size is 1200 by 630 pixels, which satisfies Facebook, LinkedIn and X's large-image card without cropping awkwardly on any of them. Keep the file size reasonable: a multi-megabyte image can slow down or fail the fetch some platforms perform when generating the preview, particularly on a slower server. Text baked into the image itself should stay well clear of the edges, since some platforms round the corners or crop slightly differently depending on the client.
Checking your work before you publish
Use our social card generator (Open Graph) to build the tag set for a page and see a rendered preview of how it's likely to appear. It's worth treating that preview as an indication rather than a guarantee: individual platforms cache, crop and truncate slightly differently, and a render that looks right in the tool can still surprise you on a specific app or client. Checking the underlying tags alongside your title tag and meta description with the Meta Tag Checker catches the common case where a page has solid SEO metadata but no social tags at all, since the two are written separately and it's easy to finish one and forget the other.
Social cards and search snippets solve related but different problems, and it helps to check both. The SERP Snippet Previewer shows how a page is likely to appear in Google's results, which depends on your title tag and meta description. A page can have a strong search snippet and a broken social card, or the reverse, because Google and social platforms are reading different fields entirely.
When this is worth the effort
Pages that get shared, guides, tools, opinion pieces, anything likely to end up posted on LinkedIn or picked up by a newsletter, deserve deliberate Open Graph tags. A standard product page on an e-commerce site that's rarely shared individually is a lower priority, though it's still worth having a sitewide fallback image so nothing renders blank. If you manage a site with hundreds of pages, it's more practical to set sensible defaults in your CMS template and only override them on the pages that matter.