declared-size.missing
og:image:width or og:image:height is missing. Level: Tip.
When it is raised
Raised when the card image loaded and the page has no og:image:width or no og:image:height in the first 300,000 characters of the HTML, outside comments. Only the first og:image:width and the first og:image:height that have a content attribute are read; if a tag's content is empty or whitespace, that tag counts as absent even when a later one has a value. twitter:image:width and twitter:image:height are not considered.
What it does to a shared link
The page does not state the image's width and height in its markup.
How to fix it
- Add og:image:width and og:image:height, in whole pixels with no unit. They are conventionally placed after og:image, though the check does not depend on order.
- Use the dimensions of the card image file as displayed, so that declared-size.mismatch is not raised.
<meta property="og:image" content="https://example.com/card.png">
<meta property="og:image:width" content="1200">
<meta property="og:image:height" content="630">