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How does Facebook detect images when adding a link?
hi all, curious how facebook is able to pull an accurate image when you post a link. I know they first look for a meta tag with the image the site owner wants them to use but if that doesn't exist what logic do you think they do to get what image should be presented if you link to a blog article let's say.
They most likely grab the source of the page and analyze it to extract the biggest images. They probably look for images close to the center of the page, images that are prominent. It's also possible that they analyze other similar pages on the site to determine unique images that aren't common across pages (this would help FB rule out images used for navigation, headers, decoration, etc.) Not sure how it determines how many perspective images to grab, though.