How can I force Facebook to purge its cache and use newer meta description of a shared webpage?

问题

Facebook fetches the title and webpage description from the HTML header of the webpage whenever people share a link on Facebook. I realized that [I believe for performance purposes], Facebook caches and reuses the webpage title and description if more people share the same link over and over again. What if the webpage has a breaking news or something that is dynamically changes within a short period of time. Even worse, what if the page had wrong content and the webmaster made changes to it?

How can I force Facebook to flush its cache and update it with new content on the website?

回答1:

The best way to do it is by using the Facebook debugger: http://developers.facebook.com/tools/debug Insert your url, let the debugger scrape your page and the cache is cleared.

UPDATE:

As DMCS pointed out "some things cannot be updated after X number of likes". Here is the info in more detail taken from the Facebook documentation:

Note: og:title and og:type are only editable initially - after your page receives 50 likes the title becomes fixed, and after your page receives 10,000 likes the type becomes fixed. These properties are fixed to avoid surprising users who have liked the page already. Changing the title or type tags after these limits are reached does nothing, your page retains the original title and type.

来源：https://stackoverflow.com/questions/9026448/how-can-i-force-facebook-to-purge-its-cache-and-use-newer-meta-description-of-a