I'm not sure if this is new behaviour or if it didn't work at all. So I'm using the LinkedIn Customized URL feature, you can look it up here. The URL looks like this:
https://www.linkedin.com/shareArticle?mini=true&url=http://developer.linkedin.com&title=LinkedIn%20Developer%20Network&summary=My%20favorite%20developer%20program&source=LinkedIn
Once I share the URL the provided summary is not shown in the post preview:
So I tried with other services like Youtube, Reddit etc. and all posts do not include the provided summary.
Unfortunately I can't provide you the open-graph tags I used on my site as it's running in a corporate environment and I'm not sure if I can provide these snippets as of now.
However, running linkedin's Post Inspector shows that it detects my summary without problems:
Values are in German if anyone wonders...
So my quick and fairly simple questions, which might be answered in a comment as well, are:
Did linkedin change something on their side? Is there some other undocumented property which neither youtube nor me included in the customized URL and therefore the summary does not show up? Is there any post from linkedin developers which note this change? Was it like that all the time or is it just a temporary thing?
LinkedIn now uses the Open Graph tags to show the preview.
Below are the og:tags that must exist and their correct format:
<meta property='og:title' content='Title of the article"/>
<meta property='og:image' content='//media.example.com/ 1234567.jpg"/>
<meta property='og:description' content='Description that will show in the preview"/>
<meta property='og:url' content='//www.example.com/URL of the article" />
And the sharing url is changed to:
https://www.linkedin.com/sharing/share-offsite/?url=your_encoded_url
Please see this Making Your Website Shareable on LinkedIn
来源：https://stackoverflow.com/questions/51189486/linkedin-sharing-url-summary-not-appearing