YouTube punishes ad-blocker users with slower videos on non-Chrome browsers

Update (November 20, 8:48 pm ET): Google has issued a statement about YouTube videos loading slower on non-Chrome browsers.

What you need to knowSeveral Reddit posts have highlighted a five-second delay when loading YouTube videos on Firefox, which disappeared when the user agent was switched to Chrome, revealing a potential browser-specific issue.Investigation by users suggests that the delay isn't a Firefox bug but an intentional addition in the JavaScript code of YouTube's desktop client.Discussions speculate that the added delay might be linked to ad display, possibly as a workaround for users employing ad blockers.YouTube's desktop site is reportedly slowing down for some people on Mozilla Firefox, causing confusion among users.
A Reddit user (u/vk6_) posted a video revealing a five-second lag loading YouTube videos on Firefox (via 9to5Google). The same Redditor demonstrated a trick to dodge the endless wait. By temporarily switching to a Chrome disguise, they tricked YouTube into believing they weren't using Firefox, and the video loaded instantly.
Eagle-eyed users quickly pinpointed the culprit behind the slowdown—a code snippet lurking in YouTube's source code. This sneaky code seems to be part of YouTube's recent anti-ad-blocking measures.
Redditor vk6_ did some digging and discovered that this isn't a Firefox glitch. Apparently, YouTube's JavaScript code has a built-in delay mechanism that intentionally holds up the video playback on desktop for five seconds. Other tech-savvy folks have even tracked down the exact location of this mischievous code in YouTube's source.

However, Android Central's editors and staff writers tried to recreate the delay, but no dice. YouTube seemed to work perfectly fine on Firefox and other web browsers we're using. We've contacted Google for an explanation anyway, and we'll keep you posted once we hear back.
Several Firefox and Edge users reported experiencing the delay even with extensions disabled, suggesting it might be an account-specific issue and that it's not just affecting Mozilla's browser. The delay reportedly happens every time a user opens a YouTube link in a new tab.
Some people have speculated that this delay might be a clumsy attempt by YouTube to force ads on users who block them. The code in question might be trying to make sure that an ad plays for at least five seconds before the actual video starts.
This isn't the first rodeo for Firefox users butting heads with Google over what feels like some intentional slowdown. Back in 2018, former Mozilla executive Chris Peterson alleged that YouTube pages load five times slower on Firefox and Edge compared to Chrome.
UpdateA YouTube spokesperson has confirmed that the YouTube slowdowns on Firefox are related to its anti-ad-blocker efforts.
"To support a diverse ecosystem of creators globally and allow billions to access their favorite content on YouTube, we’ve launched an effort to urge viewers with ad blockers enabled to allow ads on YouTube or try YouTube Premium for an ad free experience," the company said in an email to Android Central. "Users who have ad blockers installed may experience suboptimal viewing, regardless of the browser they are using."