How do I force an image to use when a website is shared? For instance when I link a URL in Google Chat, iMessage, etc. How do I determine what image, and what dimensions are used when a chat program generates a thumbnail for the link?  Example:



If I wanted this photo to not cut off the tops of these women's heads for example? I guess it just takes the first image not used for the background to use in chat? This was generated after pasting the link into Google Chat.
You can specify a specific image to use for URLs sent in iMessage by using a meta tag with og:image set to the property attribute. Apple recommends your image being at least 900px wide or larger.

Example:

&lt;meta property="og:image" content="https://www.example.com/image.png" /&gt;


I got this information from Apple’s Developer Documentation Archive.