Firefox to Fix YouTube Playback Issue by End of Month After Identifying Codec Problems

In recent years, there have been frequent discussions about Google "intentionally" degrading the performance of YouTube on browsers other than Google Chrome, including Microsoft Edge, which is based on the Trident engine, and Mozilla Firefox, based on the Gecko engine. While there is no concrete evidence to prove Google's deliberate action, adjustments made to YouTube's front and backend services sometimes cause issues on other browsers, which Google could claim as routine improvements.

A new issue has emerged in recent months affecting Firefox users, where attempting to watch YouTube videos at resolutions of 1080p and above can lead to playback failure or significant lag, such as buffering issues.

After thorough investigation, Firefox engineers have determined that the problem is not with the browser itself but is caused by YouTube providing an incorrect VP9 byte stream. This issue does not affect all users, making it difficult to replicate and thus taking several months to investigate solely on Firefox.

During these months, some YouTube users may have switched to Chromium-based browsers, including Chrome or Microsoft Edge, where the playback issue does not occur.

Firefox engineer Alastor Wu stated on Bugzilla that this problem is caused by YouTube and not a bug introduced by new Firefox versions, indicating that users on older Firefox versions might also encounter this issue.

With the root cause identified, Firefox plans to release version 127.0.2 by the end of this month to address the issue, allowing users to once again enjoy YouTube videos at 1080p resolution without disruption.