Open Graph image size

1200 × 630, roughly 1.91:1. Set it once as og:image and Facebook, LinkedIn, WhatsApp, Slack, Discord and X all use it — it is the highest-leverage image on any website.

One image, many croppers, is the thing to design around. The 1.91:1 frame is what Facebook and LinkedIn show, X uses almost the same for a large summary card, but several chat apps crop toward square, so a design with text running to the left and right edges loses it in Slack or WhatsApp. Keeping the important part in a centred square inside the 1200 × 630 solves it. Two practical rules: use an absolute URL for og:image, since relative paths silently fail, and remember that Facebook caches aggressively — changing the image does not change the preview until you refresh it through their Sharing Debugger.