Title
Shown as the card's headline. Falls back to the app title.
Site name
og:site_name. Slack shows it above the title.
Description
One or two sentences. WhatsApp shows about two lines of it.
Canonical domain
https://example.com. Every card URL is built from it, and a relative image cannot be used without it.
Type
ogp.me's object type. `website` unless this is a blog.
Locale
language_TERRITORY, e.g. en_US.
Card image
1200x630. Under ~300KB or WhatsApp shows a small icon instead.
Card image
1200x630. Under ~300KB keeps WhatsApp's large card.
Image description
og:image:alt. What is in the picture, not a caption.
X and Facebook
Everything else is read from the tags above.
Card layout
The only thing X does not take from og:*.