image-alt.missing
og:image:alt is missing. Level: Tip.
When it is raised
Raised when the card image (og:image, or twitter:image when og:image is not set) loads as an image and neither og:image:alt nor twitter:image:alt has non-empty content in the first 300,000 characters of the HTML, outside comments. Only the first tag of each name that has a content attribute is read; if its content is empty or whitespace, that tag counts as absent even when a later one has a value. It is not raised when there is no image or the image fails to load.
What it does to a shared link
The page supplies no text description of the card image for screen-reader users.
How to fix it
- Add an og:image:alt tag that describes what the image shows.
- Keep it to a plain sentence describing the picture rather than repeating the title.
<meta property="og:image" content="https://example.com/card.png">
<meta property="og:image:alt" content="Bar chart of monthly sign-ups for 2026">