Question

When my page is shared on Facebook or LinkedIn, it always picks something random or inconsistent from the page to choose the title, images, and description. How do I force the social networks to use explicit values for those fields. Do I need meta data in my page head for each? The info seemed scattered and outdated over the web so I appreciate any help.

Answer 1

On LinkedIn, if you are sharing using the website or a share button, open graph tags in the page will be honored as detailed here:
https://developer.linkedin.com/documents/setting-display-tags-shares

Note that if you have already shared a page it won’t get re-scraped for 7 days and there’s no way to force a quicker re-scan.

Edited (Mousey)
Facebook link for rescraping, checking which image etc will be found and checking opengraph meta tags https://developers.facebook.com/tools/debug/

LinkedIn will rescrape if you add a parameter on the end, as described in http://beta.beantin.se/clearing-linkedin-link-sharing-preview-cache/

Edit 2022 (Studocwho)

Linkedin now has a Post Inspector which gives you detailed information and debugging, and as a result it also refreshes and re-scrapes the page. It’s available here: https://www.linkedin.com/post-inspector/.

This resource was found from this article: https://www.linkedin.com/pulse/how-clear-linkedin-link-preview-cache-ananda-kannan-p/

Apologises unable to post this as a comment