YouTube has been cracking down on ad blockers in recent months, urging users to disable ad blockers on the platform or subscribe to YouTube Premium. Now, the Google-owned platform may have taken it a step further: Firefox users have reported noticeably longer load times on YouTube's desktop site, which seems to be a deliberate choice on Google's part.

Redditor u/vk6_ recently shared a video showing a 5-second delay when loading YouTube in Mozilla's Firefox web browser. For a few seconds, the page remains mostly blank, with background elements but no video. After a short delay, the page loads normally. Other Redditors encountered the same problem, claiming that YouTube takes significantly longer to load in Firefox and Edge, but no wait time in Chrome. Annoyingly, users stated that this delay does not occur only once, but every time they open a YouTube link.

Upon analyzing the JavaScript files used by the YouTube client on the desktop, one user found code in the script indicating a "timeout" function. The code itself does not specifically identify Firefox or Edge, but some users have found that using a filter on this code seems to solve the problem. Others have reported that when they spoofed Firefox's user agent to make it look like Chrome, YouTube loaded just as fast as normal, with no more than a five-second delay. Even stranger, 9to5 Google conducted a reverse experiment and found that this delay did not occur when Chrome was disguised as Firefox.

Some users suggested that this may be related to the crackdown on ad blockers. Several users postulated that if a user is using an ad blocker, the associated code could be a clumsily implemented ad fallback so that the ad is displayed for at least 5 seconds before the video starts.

A YouTube spokesperson said that users with ad blockers installed "may not have an optimal viewing experience" no matter which browser they use:

"We support a diverse ecosystem of creators around the world and billions of To help ensure that their favorite content is accessible on YouTube, we have launched an initiative to encourage viewers with ad blockers enabled to allow ads on YouTube or try ad-free YouTube Premium. Users with ad blockers installed may experience less than optimal viewing regardless of the browser they are using.