# CodePen embed no longer working

**URL:** https://meta.discourse.org/t/codepen-embed-no-longer-working/386399
**Category:** Support
**Tags:** onebox, embedding
**Created:** [October 22, 2025, 5:06am UTC](https://meta.discourse.org/t/codepen-embed-no-longer-working/386399 "2025-10-22T05:06:23Z")
**Posts on this page:** 5
**Page:** 1

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### Author: ![trusktr](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/trusktr/32/116841_2.png) [@trusktr](https://meta.discourse.org/u/trusktr)
#### Post date: [October 22, 2025, 5:06am UTC](https://meta.discourse.org/t/codepen-embed-no-longer-working/386399/1 "2025-10-22T05:06:23Z")

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CodePen in the Three.js forum is no longer working:

> **[Have new codepen embeds been disallowed in the forums?](https://discourse.threejs.org/t/have-new-codepen-embeds-been-disallowed-in-the-forums/82303)**
>
> For example: https://codepen.io/trusktr/pen/ZEZYZYe I see this:

What config setting could have changed that disables CodePen embeds?

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### Author: ![jahan\_gagan](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/jahan_gagan/32/501948_2.png) [@jahan\_gagan](https://meta.discourse.org/u/jahan_gagan)
#### Post date: [October 22, 2025, 8:33am UTC](https://meta.discourse.org/t/codepen-embed-no-longer-working/386399/2 "2025-10-22T08:33:20Z")

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Check your `allowed_iframes` site setting and make sure the CodePen embed URL pattern is listed there.  
Also verify that `allowed_onebox_iframes` isn’t too restrictive.  
Finally, confirm that `codepen.io` isn’t included in `blocked_onebox_domains`.

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### Author: ![Moin](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/moin/32/554653_2.png) [@Moin](https://meta.discourse.org/u/Moin)
#### Post date: [October 22, 2025, 9:03am UTC](https://meta.discourse.org/t/codepen-embed-no-longer-working/386399/3 "2025-10-22T09:03:26Z")

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The CodePen entry in `allowed_iframes` was changed a few months ago in [Security fixes for main by tgxworld · Pull Request #33117 · discourse/discourse · GitHub](https://github.com/discourse/discourse/pull/33117)

 ![Screenshot_20251022_110154_Firefox](https://global.discourse-cdn.com/meta/original/4X/d/2/e/d2e7c143719b48a545242f3f86c76a9db9df4edd.jpeg)

Maybe your links don’t match the new allowed format.

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### Author: ![tobiaseigen](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/tobiaseigen/32/539204_2.png) [@tobiaseigen](https://meta.discourse.org/u/tobiaseigen)
#### Post date: [November 3, 2025, 10:53pm UTC](https://meta.discourse.org/t/codepen-embed-no-longer-working/386399/4 "2025-11-03T22:53:38Z")

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Hi Joe! Were you able to resolve your issue? If so let us know so we can close this topic.

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### Author: ![tobiaseigen](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/tobiaseigen/32/539204_2.png) [@tobiaseigen](https://meta.discourse.org/u/tobiaseigen)
#### Post date: [December 3, 2025, 10:54pm UTC](https://meta.discourse.org/t/codepen-embed-no-longer-working/386399/5 "2025-12-03T22:54:15Z")

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