Make an Open Graph image for link previews

It is an image your page declares in a meta tag, and platforms read that tag when someone shares your link. Because it comes from the page and not from the person sharing, one image serves every share of that URL. Producing the file is only half the job: the page still has to point at it with an og:image tag, and most platforms need an absolute URL rather than a relative one.

Because platforms cache what they scraped the first time, often for days. Replacing the file at the same URL usually is not enough. Most platforms provide a debugging tool that re-scrapes a URL on demand, and changing the image's filename so the URL itself is new is the reliable fallback.

Keep it short and large if you do. The card is rendered small in a phone feed, and platforms crop the edges differently, so anything near the border can vanish. A headline of a few words centred well inside the frame survives; a paragraph does not, and neither does text that relies on being read at full size.

They read the same tag and render it at broadly the same shape, which is why one wide image works across them. They differ at the margins - some crop slightly more, some show a square in chat, and some fall back to a thumbnail if the image is small. The square option here exists for the chat case.

It is what independent references consistently report and what the major platforms visibly render at, which is how this page labels it. The Open Graph protocol itself does not mandate a pixel size; the platforms reading the tag decide. Nothing on this page is presented as a published specification, because none of them was re-read while it was written.