I'm not sure what sort of action you mean, but Facebook doesn't fetch the page in real-time using the client's browser. Some sort of job scrapes the page HTML l

I'm not sure what sort of action you mean, but Facebook doesn't fetch the page in real-time using the client's browser. Some sort of job scrapes the page HTML looking for metadata and then uses that metadata to populate the preview. If you want to play around with what it "sees", you can test using the sharing debugger: https://developers.facebook.com/tools/debug/ https://developers.facebook.com/tools/debug/