Why Do Some Blog Posts in Discourse Have A Preview?

I am not sure if this is a Wordpress question or a Discourse questions but hopefully someone here will be bale to help me out. On my Discourse site - If I post a link like this one:


It will show me this preview:

Other blog post links like this one only give me the URL:


Does anyone know why?

Thank you,

It’s my understanding this is a function of discourse/onebox.

Doesn’t appear to work with WordPress installations. Because it doesn’t pull in our regular site either.


Not sure why this is, but hopefully at least gets half of your question answered :slight_smile:

… had to try one more time :wink:

1 Like

Discourse oneboxes do work with WordPress sites. If a link fails to onebox, it is likely because either the page it links to is missing the necessary Open Graph data, or because the request from Discourse is being blocked by the website’s server.

You can check the Open Graph data for a URL here: http://iframely.com/debug.

The website you are trying to link to is hosted by WPEngine. They are blocking requests from the Discourse Forum Onebox user agent. To allow sites hosted by WPEngine to create oneboxes on Discourse, the owner of the site needs to contact WPEngine and ask them to allow the Discourse Forum Onebox User Agent. If you are the owner of the website, it would be great if you could contact WPEngine support and ask about this. We would like them to allow requests made with the Discourse Forum Onebox User Agent by default.


WPEngine is known to blacklist https requests from user-agents they don’t like @jameshahnii.

(I deleted the extremely verbose support chat you posted since it can be correctly summarized with the previous sentence I just wrote.)


Hi Guys,

I appreciate the responses. I learned two things:

  1. That feature is called onebox.

  2. I probably should have used an example from my own blog that is not working with onebox. I run the blog on WordPress and it is hosted by BlueHost. This is a sample link that is not working:

The blog is not finished yet so please ignore the layout issues you might see. The forum is hosted by Digital Ocean at:

I would appreciate if anyone knows how I can get my own blog posts to be recognized by onebox.

Thank you,

The problem with https://sobervegan.com/hey-honey-are-you-vegan/ is that the page it points to is missing the Open Graph tags that Discourse needs to find before it can create a onebox.

Searching Google for ‘add open graph tags wordpress’ returns some good results. This page gives a few options for how to do it: How To Add Open Graph Meta Tags To WordPress | Elegant Themes Blog.


Thank you Simon. I will check it out and see if I can learn more about this. I appreciate your help.

  • Scot

I’m bumping this thread to report that URL previews are now working for WP Engine sites.