Hello there! On our forum, we’ve seen some recent changes to how links to sites on our domain (makecode.com) are embedded by onebox. Previously, you got a little minimal preview like this: [image] However, we’re now seeing a more advanced embed where the actual site is hosted in an iframe when the same link is pasted into new posts: [image] Was there an update made in last few days to onebox and, if so, is there a way to revert to the old behavior? As far as we are aware, we haven’t made any recent changes on our side. For reference: Here is a link to the post from the first image: Falling blocks multitasking - Show & Tell - Microsoft MakeCode Here is a link to the post from the second image: Changes to link embeds - Forum Feedback - Microsoft MakeCode And here is the link that both posts are embedding: falling blocks insanity

Your first post has pretty normal looking onebox code: [image] But your second post is doing something different with a pxtoembed class and an iframe: [image] Are you sure there have been no changes? I don’t know much about setting up iframing but there’s an admin setting for “Allowed onebox iframes” you might take a look at.

Thanks for taking a look! I’m fairly certain there have been no changes; I did take a look at that setting and it simply had the default value (“*”). I just tried removing that wildcard and replacing it with a single domain (YouTube) but it doesn’t seem to have had any effect on the embed. That pxtoembed class and iframe that you screenshotted come from the oembed endpoint that we link in the embedded page: [image] However that’s been there for years, I’m not sure why it suddenly started getting embedded today.

[image] riknoll: I just tried removing that wildcard and replacing it with a single domain (YouTube) but it doesn’t seem to have had any effect on the embed. Did you try rebuilding the post’s HTML after that (Post 3 dots > Admin wrench > Rebuild HTML)?

Just gave that a shot, but no dice! The embed is still there and still shows up when I create a new post with the same link.

Alright, turns out there are two iframe settings in the Security section, and my domain was still added in the other one. I’ve now removed that one and it has at least prevented the issue for now! Still not sure why this suddenly started happening…

Recent changes to Onebox embedding for my site

Product Support

NateDhaliwal (Nate Dhaliwal) January 16, 2026, 9:42am 4

Did you try rebuilding the post’s HTML after that (Post 3 dots > Admin wrench > Rebuild HTML)?

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