问题
My page, after adding an SSL certificate (Let's Encrypt), cannot have preview fetched by Facebook or Twitter when sharing the link. I have followed The Open Graph protocol and include the following open graph tags:
<meta property="og:type" content="article" />
<meta property="og:title" content="Corner Timer: gently make you feel guilty on time-wasting apps" />
<meta property="og:url" content="https://lyminhnhat.com/resources/productivity/corner-timer-gently-make-you-feel-guilty-on-time-wasting-apps/" />
<meta property="og:description" content="Make you feel guilty for your unproductive curiosity" />
<meta name="twitter:site" content="@ooker777" />
<meta name="twitter:text:title" content="Corner Timer: gently make you feel guilty on time-wasting apps" />
<meta name="twitter:image" content="https://lyminhnhat.com/wp-content/uploads/2019/04/Screenshot_2019-04-11-11-31-39.png?w=640" />
<meta name="twitter:card" content="summary_large_image" />
However, all 3 Open Graph checkers I use - OpenGraphCheck.com, Abhinay Rathore's Open Graph Tester, Facebook's Object Debugger - say that there is no Open Graph implement. There is one exception though: Iframely's Embed Codes
Since all three checkers have problem with this, probably this is not just a problem of of Facebook, as suggested in FB OpenGraph og:image not pulling images (possibly https?). Nevertheless, nothing changes even though I have tried using html links only, stripping end white space, using <html prefix="og: http://ogp.me/ns#">.
This person suggests that it can be a server issue. Do you know why this happens?
Related: Would having a fresh website with SSL already avoid Open Graph problem?
回答1:
In my case, it seems that the crawler is just having a bug. I have my own canonical answer in this question, hope that helps someone: FB OpenGraph og:image not pulling images (possibly https?)
来源：https://stackoverflow.com/questions/57529664/why-cant-open-graph-checkers-detect-open-graph-data