YouTube Code Slows Down Video Loading in Firefox, New Study Finds

A recent issue has emerged for YouTube users who have noticed a delay of about five seconds when loading videos on the Firefox browser. This delay has been linked to the use of ad blockers and Google’s efforts to combat these programs.

A user, identified as vk6, shared their experience on Reddit by showing that when playing a video on YouTube using Firefox, there is a delay with a black screen before the video starts. However, when using Chrome, the video plays automatically without any delay.

The reason for this delay is believed to be related to ad blocking extensions in the Firefox browser. Specifically, in the uBlock Origin Reddit forum, it has been claimed that the delay is not a Firefox bug, but rather a code implemented by Google on YouTube, identified as 5E3 in the polymer script link.

YouTube confirmed in early November that it was implementing global measures to combat ad blockers in browsers, including increased warnings urging users to avoid their use or to subscribe to YouTube Premium. In addition, the platform may block the playback of the video if ad blockers are detected.

This battle against ad blockers has resulted in an increase in uninstalls and installations of ad blocking software such as AdGuard, AdLock, and Ghostery. Privacy activist Alexander Hanff has reported this to the Irish Data Protection Commission (DPC), alleging that YouTube’s blocker detection system uses JavaScript code which may be illegal under European Union law.