OG image

An OG image is the picture that appears when someone shares your URL. It is declared with the og:image meta tag from the Open Graph protocol, and it is read by X, LinkedIn, Slack, Discord, Facebook, iMessage and most chat clients.

The working size is 1200 by 630 pixels, a 1.91 to 1 ratio. Under about 600 by 315 most platforms fall back to a small square thumbnail. Declare og:image:width and og:image:height so clients can lay out the card before downloading the file, and provide an absolute URL, since relative paths fail on several platforms.

Alongside it you want og:title, og:description, og:url, og:type and twitter:card set to summary_large_image.

Two practical notes. Platforms cache aggressively, so a fixed image may keep appearing for days after you change it. And the image is often rendered at thumbnail size in a crowded feed, so large type and high contrast beat a screenshot of your interface almost every time.

Directories frequently generate an OG card automatically from your logo, tagline and category when you do not supply one, which is better than nothing and worse than a card you designed.