YouTube is loading slower for users with ad blockers on all browsers [U]

YouTube has started cracking down on ad blockers, and now, that includes slowing down the loading time for anyone who has an ad blocker installed on any browser.

Update 11/21: In an updated statement to 9to5Google, YouTube explains that ad blocker detection is the cause of “suboptimal viewing” on YouTube.com, including this new slower loading behavior.

Ads are a vital lifeline for our creators that helps them run and grow their businesses. That’s why the use of ad blockers violate YouTube’s Terms of Service. We’ve been urging users for some time to allow ads on YouTube or try YouTube Premium for an ad-free experience. In the past week, users using ad blockers may have experienced suboptimal viewing, which included delays in loading, regardless of the browser they are using. Users who have uninstalled their ad blockers may still experience a temporary delay in loading, and should try refreshing their browser.

While this was first noticed with Mozilla Firefox, as our coverage below goes over, YouTube says that its ad blocker detection does not target specific browsers and that this behavior may be seen on any browser with an ad blocker installed.

Our original coverage and YouTube’s previous statement follow:

Loading up YouTube.com is something many folks do on a daily basis, but recently, that process has been weirdly slow for some, specifically on Firefox.

Redditor u/vk6_ posted a video that shows YouTube loading up on Firefox with a significant delay. For a few seconds, the page is mostly blank, with background elements showing but no content to accompany it. After a few seconds, the page loads up as usual.

One might assume this is simply a connection issue, but the video shows pretty clearly that this is a choice by Google. When spoofing the user agent of Firefox to make it appear to be Chrome, YouTube loads up completely as normal. There’s no wait time, and the loading as a whole is drastically faster.

At a glance, it really seems like clear evidence that this is a choice on Google’s part, and there might be even more to it. Another user found code on YouTube.com that shows a “timeout” function in the script that forces users to wait five seconds before the page loads. However, some believe this may be related to the ad-blocker crackdown. The code itself doesn’t seem to point to Firefox in particular, but some users have found that using a filter for this code seems to fix the loading times.

Also notable, we tried this in the other direction. Spoofing Chrome to act as Firefox does not push this delay into effect.

But it’s hard to say anything for certain.

Update: In response to 9to5Google, Google pointed to ad blockers as the apparent reason for this slowdown, saying that “users who have ad blockers installed may experience suboptimal viewing, regardless of the browser they are using.”

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. Users who have ad blockers installed may experience suboptimal viewing, regardless of the browser they are using.

While this doesn’t address the question of why loading was faster when Firefox was spoofing itself as Google Chrome, it does line up with this particular user having an ad blocker installed, as is barely visible in the video in Chrome’s top bar. In our testing from Chrome spoofing as Firefox, notably, no such ad blockers were installed.

If you are seeing YouTube.com loading slowly on Firefox and you do not have an ad-blocker installed, let us know in the comments below.

The reasoning for this is unclear, but it comes at a less-than-ironic time. Amid the crackdown on ad-blockers and Chrome’s removal of Manifest V2 extensions (which will break some ad-blockers), Firefox has been a spot for many folks to go to.

The other explanation could simply be a technical bug, but it’s hard to say what that might be. Firefox does run on the Gecko browser engine as opposed to the more widely used Blink on Chrome, Edge, and others, and WebKit, which is used on Safari, but spoofing the browser with an extension doesn’t change the engine being used, which, again, suggests this has something specifically to do with Firefox. Our Kyle Bradshaw suggests that it could be as simple as the codebase being used for the Gecko engine having a delay for testing that mistakenly made it to production. The fact that this doesn’t happen when spoofing Chrome to act as Firefox, too, supports the idea that this is more of a technical issue.

In any case, it’s a very frustrating issue and pretty wild to see.

Google has, so far, not acknowledged the issue.

More on YouTube:

• YouTube makes official latest Premium features, like enhanced 1080p
• YouTube will show labels on videos that use AI
• YouTube adding ‘For You’ channel section that tailors video recommendations for new viewers

Update: This post has been updated to reflect testing where spoofing Chrome to act as Firefox does not show the same delay.

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