How Facebook link preview happens?

Question

When you type a URL into facebook, it automatically comes up with the \"post a link\" feature. With most websites, it automatically loads a selection of images it pulls from som

Answer 1

Surprisingly there aren’t that many services out there doing this. As the previous commenter posted, your browser can’t do this without a server element.

So, the workflow is really this:

1. Parse the inserted text to test it’s a valid URL
2. Whiz that URL value via AJAX to a bespoke service or roll your own.
3. The service (mine is written in .Net) loads up the page in memory and parses it with an DOM parser. I use the HTML Agility pack you could use AngleSharp etc.
4. You need to extract the Open graph meta elements with (typically) fall back to standard Meta Title/ Description et all.
5. Pack up all that OG goodness and return this model via AJAX
6. Put the returned values on screen as a preview.
7. If accepted write the logic to insert the values into your DB

If you are not up to creating the server object, there are third-party services that can do the retrieval bits:

http://unfurl.oroboro.com/

https://guteurls.de/

best of luck.