No sharing preview (Open Graph)

On a live page we look for the Open Graph elements that drive the share preview: og:title and og:description. The finding is raised only when both are missing at once. One of them is enough for silence.

A missing og:image is not enough on its own, and that is deliberate: not every page has something to show, and demanding an image on a text subpage would be pestering.

What the check does not do:

• It does not judge the contents of the elements. An og:title identical to the site name on every page passes.
• It checks neither Twitter Card (twitter:*) nor og:type, og:url and og:site_name.
• It does not verify that the image exists or has a sensible size. A broken URL in og:image shows up nowhere.
• It ignores elements injected by JavaScript. No social network would read those anyway, since none of them runs scripts when generating a preview.

The finding is page-level and informational. It costs no score at all: it is the least consequential item in the whole core set, and the next section explains why.

We will be straight about this, because there is nothing to dress up: Open Graph has no documented effect on how a search engine or a language model understands your page. It is neither a necessary condition nor a measured effect. It is the weakest item in the core set, and it is in this manual chiefly so that expectations are clear.

Open Graph is a protocol by which a page tells social networks and chat applications what its preview should look like when somebody shares a link. Facebook, LinkedIn, Slack, Discord, WhatsApp and Signal read it. Search engines do not need it to understand a page; they have <title>, <meta name="description"> (STR-03) and the content itself.

So why keep the check? Because sharing a link is still one of the real ways content reaches people, and a link that shows up in Slack as a bare URL gets clicked less than one with a headline and a sentence. That is marketing, not readability. We say it plainly so that nobody imagines it will improve their position in AI answers.

When to skip it without guilt: admin areas, internal tools, pages behind a login and anything that never gets shared. There, Open Graph is wasted work and the finding can be ignored. That is exactly why it is informational and costs no score.

These four elements belong in the <head>. og:title and og:description clear the finding; og:image and og:url are what make the preview usable:

<meta property="og:title" content="Heat pump servicing within 48 hours">
<meta property="og:description" content="An engineer on site the next day, for scheduled inspections and breakdowns alike. From £90.">
<meta property="og:image" content="https://your-domain/preview.jpg">
<meta property="og:url" content="https://your-domain/servicing">

Watch one detail that trips people up more than any other: Open Graph uses property, not name. An element written as <meta name="og:title"> is invalid under the protocol and most networks will skip it, even though it looks identical in a browser and is easy to miss in code.

The rest is practical detail that decides whether anyone sees the preview at all:

• Generate the elements from your template, from the same source as <title> and the meta description. Hand-written Open Graph on a thousand pages is unmaintainable.
• og:image must be an absolute URL (https://…), never a relative path. This is the second most common mistake after name instead of property.
• A sensible size is 1200 × 630 px. A smaller image gets shown by most networks as a small square thumbnail beside the text rather than a large preview.
• The image must be publicly reachable. The network fetches it itself, without your cookies and without a login; an image behind authentication will not appear.
• Previews are cached. After a fix, networks may keep showing the old version for a long time; most of them offer a tool to force a refresh.

You can check the result without any tool: paste the link into whatever chat you use and look at what comes out.