Check the preview before you post it

Paste a link. Metaglance shows the card most platforms will build from it and lists the tags behind that card, including the ones you forgot.

Nothing inspected yet.

The tags that actually matter

og:title: Falls back to <title>. Keep it under roughly 60 characters or it gets clipped.
og:description: Two lines on most platforms. Write it for a human, not for a crawler.
og:image: Use an absolute URL. 1200×630 is the safe size. Relative paths are the single most common mistake.
og:url: The canonical address. Without it, tracking parameters end up in shared links.
twitter:card: summary_large_image for a big image, summary for the compact form.

Cards are cached aggressively once a link has been shared. If you fix a tag after posting, expect the old preview to stick around for a while.