YouTube artificially slows down video load times when using Firefox

Re:YouTube artificially slows down video load times when usi... by lifthrasiir on Monday November 20, 2023 @06:39AM (#38346602)

That is not correct. The surrounding code gives some more context:

    h=document.createElement("video");l=new Blob([new Uint8Array([/* snip */])],{type:"video/webm"});
    h.src=lc(Mia(l));h.ontimeupdate=function(){c();a.resolve(0)};
    e.appendChild(h);h.classList.add("html5-main-video");setTimeout(function(){e.classList.add("ad-interrupting")},200);
    setTimeout(function(){c();a.resolve(1)},5E3);
    return m.return(a.promise)})}

As far as I understand, this code is a part of the anti-adblocker code that (slowly) constructs an HTML fragment such as `<div class="ad-interrupting"><video src="blob:https://www.youtube.com/..." class="html5-main-video"></video></div>`. It will detect the adblocker once `ontimeupdate` event didn't fire for 5 full seconds, which is the actual goal for this particular code. I do agree that the anti-adblocker attempt itself is still annoying.

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Re:YouTube artificially slows down video load times when usi... by gear54rus on Monday November 20, 2023 @06:49AM (#38346694)

Seconded. This title is therefore sensationalist and has to be edited.

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Re:YouTube artificially slows down video load times when usi... by makeitdouble on Monday November 20, 2023 @07:17AM (#38346920)

This gives us some background, but it's still slowing down firefox with no relation to the video content.

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Re:YouTube artificially slows down video load times when usi... by insanitybit on Monday November 20, 2023 @07:46AM (#38347191)

It's radically different.

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Re:YouTube artificially slows down video load times when usi... by Ygg2 on Monday November 20, 2023 @07:03AM (#38346805)

How come switching to User Agent to Chrome fixed it for that Reddit OP? Does it omit this if UA is changed?

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Re:YouTube artificially slows down video load times when usi... by gear54rus on Monday November 20, 2023 @07:09AM (#38346857)

When they first introduced anti-adblock crap, you could evade the banner by switching UAs. I'd say it's fair to assume that switching UAs triggers some other code path and this function never gets called.

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Re:YouTube artificially slows down video load times when usi... by lifthrasiir on Monday November 20, 2023 @06:51AM (#38346710)

For the completeness, the omitted Uint8Array is the following 340-byte binary (here in base64):

    GkXfo59ChoEBQveBAULygQRC84EIQoKEd2VibUKHgQRChYECGFOAZwH/////////FUmpZpkq17GD
    D0JATYCGQ2hyb21lV0GGQ2hyb21lFlSua6mup9eBAXPFh89gnOoYna+DgQFV7oEBhoVWX1ZQOOCK
    sIEBuoEBU8CBAR9DtnUB/////////+eBAKDMoaKBAAAAEAIAnQEqAQABAAvHCIWFiJmEiD+CAAwN
    YAD+5WoAdaGlpqPugQGlnhACAJ0BKgEAAQALxwiFhYiZhIg/ggAMDWAA/uh4AKC7oZiBA+kAsQEA
    LxH8ABgAMD/0DAAAAP7lagB1oZumme6BAaWUsQEALxH8ABgAMD/0DAAAAP7oeAD7gQCgvKGYgQfQ
    ALEBAC8R/AAYADA/9AwAAAD+5WoAdaGbppnugQGllLEBAC8R/AAYADA/9AwAAAD+6HgA+4ID6Q==

VLC somehow refuses to play it, but its nominal length can be verified with a short JS code like:

    v = document.createElement('video');
    v.src = `data:video/webm;base64,<as above>`;
    await new Promise(resolve => v.onloadedmetadata = resolve);
    console.log(v.duration);

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Re:YouTube artificially slows down video load times when usi... by FoodWThrow on Monday November 20, 2023 @07:01AM (#38346796)

Why is it only trying to detect ads when the user agent is Firefox?

https://old.reddit.com/r/firefox/comments/17zdpkl/this_behav...

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Re:YouTube artificially slows down video load times when usi... by lifthrasiir on Monday November 20, 2023 @07:06AM (#38346836)

I have no idea because I didn't experience anything like that both in Chrome and in Firefox (both with uBO though). But I'm confident that this particular code is not related to the actual slowdown, if it did happen to some Firefox users, because I received the same code even in Chrome.

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Re:YouTube artificially slows down video load times when usi... by timeon on Monday November 20, 2023 @07:34AM (#38347074)

This is just anecdote, but sometimes (especially when I'm on slower internet) Safari + AdGuard will have glitch [0] on YouTube. Never happened with Firefox + Ublock Origin.

[0] Unable to press play and showing image with Ad instead.

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Re:YouTube artificially slows down video load times when usi... by c-fe on Monday November 20, 2023 @08:00AM (#38347345)

I experience the same glitch and i like it because you can just reload the page (cmd-r) and then the video starts so if you're used to it you can skip ads within less than a second and you dont get annoyed by the ad sound/video, just an image.

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Re:YouTube artificially slows down video load times when usi... by dash2 on Monday November 20, 2023 @07:29AM (#38347032)

Does Firefox allow a wider range of plugins, including adblockers?

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Re:YouTube artificially slows down video load times when usi... by TexanFeller on Monday November 20, 2023 @07:32AM (#38347054)

Yes, Chrome is severely hobbled in this by comparison.

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Re:YouTube artificially slows down video load times when usi... by GTP on Monday November 20, 2023 @08:31AM (#38347715)

Yes, there are plenty. You can have a look here: https://addons.mozilla.org/en-US/firefox/

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Re:YouTube artificially slows down video load times when usi... by pgt on Monday November 20, 2023 @07:11AM (#38346877)

I would suspect because Google can do the detection in Chrome itself, but not in Firefox.

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Re:YouTube artificially slows down video load times when usi... by GuB-42 on Monday November 20, 2023 @08:02AM (#38347364)

Probably because there are other methods for Chrome that don't apply to Firefox.

Like when I noticed that some sites did some URL rewriting trickery on Firefox and others browsers, but not for Chrome. The trick is to show you the proper URL the link points to, but as you click, it is substituted for one that is a redirection, for tracking purposes (ex: "https://l.facebook.com/l.php?u=http:://actualsite..."). On Chrome, they don't need to use these tricks as the browser supports the "ping" attribute of links, so they can do their tracking without rewriting the URL.

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Re:YouTube artificially slows down video load times when usi... by shantara on Monday November 20, 2023 @08:26AM (#38347643)

I've also noticed this behavior popping up a lot lately, but I had no idea why. The URL with tracking included was still blocked by uBlock Origin, but having to manually copy-paste the relevant portion was an annoyance.

Thanks for the context!

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Re:YouTube artificially slows down video load times when usi... by seba_dos1 on Monday November 20, 2023 @05:55PM (#38356115)

Check out ClearURLs extension.

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Re:YouTube artificially slows down video load times when usi... by Thiez on Monday November 20, 2023 @08:22AM (#38347589)

Wow, that is pretty disgusting behavior.

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Re:YouTube artificially slows down video load times when usi... by shadowgovt on Monday November 20, 2023 @12:57PM (#38351607)

The web developer interprets missing features as damage and polyfills around them.

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Re:YouTube artificially slows down video load times when usi... by JohnFen on Monday November 20, 2023 @06:43PM (#38356659)

This kind of BS is why I don't ever click on links directly. I copy/paste them instead, so I can examine and trim them. Often, the actual link is through some sort of redirection service and I need to copy/paste the text the browser shows for the link rather than the actual link.

There's so much trickery and nonsense around this stuff that no link is safe to just click on.

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Re:YouTube artificially slows down video load times when usi... by l8rlump on Monday November 20, 2023 @10:30PM (#38358733)

Check out the Privacy Badger extension. I believe it removes the tracking stuff from (some) links.

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Re:YouTube artificially slows down video load times when usi... by vanderZwan on Tuesday November 21, 2023 @04:25AM (#38361373)

There are also dedicated link cleaning extensions (I use Neat Url).

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Re:YouTube artificially slows down video load times when usi... by flexagoon on Wednesday November 22, 2023 @01:11AM (#38375333)

You actually don't need to use any dedicated extensions for that, as this functionality is built into uBO, you just need to find a filter list (just search for "ublock origin clearurl list" or whatever)

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Re:YouTube artificially slows down video load times when usi... by vanderZwan on Friday November 24, 2023 @12:42PM (#38406305)

Does it work on links copied from the page for chats?

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Re:YouTube artificially slows down video load times when usi... by JohnFen on Tuesday November 21, 2023 @10:39AM (#38365087)

I use privacy badger, but it doesn't cover everything so I end up having to manually check all links anyway.

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Re:YouTube artificially slows down video load times when usi... by timeon on Monday November 20, 2023 @07:29AM (#38347024)

It is still better to wait 5s without ad than with ad.

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Re:YouTube artificially slows down video load times when usi... by lifthrasiir on Monday November 20, 2023 @07:34AM (#38347075)

It has to be a background check, otherwise you can't explain cases (like me) where the code is running but users never noticed any delay.

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Re:YouTube artificially slows down video load times when usi... by tzs on Monday November 20, 2023 @12:37PM (#38351235)

I wonder if it is just a coincidence is that 5s is the time before a skippable ad becomes skippable?

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Re:YouTube artificially slows down video load times when usi... by 1905 on Monday November 20, 2023 @06:12PM (#38356304)

Either wait 5 seconds without ad, or get served an ad about switching to Chrome

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Re:YouTube artificially slows down video load times when usi... by Aardwolf on Monday November 20, 2023 @09:16AM (#38348519)

I couldn't reproduce the 5s wait in multiple scenarios in Firefox (various combinations of being logged in / not being logged in / without adblocker / with adblocker) and couldn't reproduce a 5s wait time in any of them, it played back immediately in each case (when without adblocker, using a second video to have one start without ad). I tested on Linux.

What exact combination of circumstances is required to trigger the multi second wait time?

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Re:YouTube artificially slows down video load times when usi... by Vvector on Monday November 20, 2023 @09:37AM (#38348876)

I can't reproduce this either. YT on FF plays immediately for me

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Re:YouTube artificially slows down video load times when usi... by rez9x on Monday November 20, 2023 @11:52AM (#38350384)

I tested in Firefox (uBlock), LibreWolf (uBlock), Safari (AdGuard), and Chromium (no ad blocker), and the initial home page load takes a couple seconds, but I never witnessed a 5s delay. I would say it was actually fastest in Firefox for me, but that may have just been a result of some caching. I am a premium subscriber and have never seen a warning for using an ad blocker, so I'm not sure if premium subscribers get a pass.

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Re:YouTube artificially slows down video load times when usi... by nixass on Monday November 20, 2023 @12:21PM (#38350927)

I am experiencing delay on both Firefox and Waterfox

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Re:YouTube artificially slows down video load times when usi... by kortex on Monday November 20, 2023 @12:35PM (#38351210)

I just tested this in firefox on ubuntu. Three subsequent new tab tests.

Load: 4.34s, 5.14, 2.96, 3.35

DOMContentLoaded: 3.65s, 4.56, 2.92, 3.33

Finish: 13.14s, 10.77, 8.49, 12.02

So it's getting a bit faster over time, but still heinous, and crucially, it isn't hanging on requests. Individual asset GET/POST requests are taking tens of ms, worst was a few parallel 254ms GETs on a cold start. Usually 50-70ms. But there is a flurry of requests, then a period of very few requests until 5s after init, then another flurry.

Firefox 119.0 Ubuntu 22.04 uBlock Origin, Privacy Badger

Same OS, chrome 115.0.5790.170, no blockers, youtube is much snappier, it still definitely takes a few seconds to paint thumbnails, but it's basically done by 5s.

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Re:YouTube artificially slows down video load times when usi... by rendaw on Monday November 20, 2023 @12:13PM (#38350763)

Okay, I'm sold on the delay, but where's the code that detects non-chrome?

Do they serve different js based on the user agent header? If they delay chrome too there's no foul.

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Re:YouTube artificially slows down video load times when usi... by Quot on Monday November 20, 2023 @12:17PM (#38350843)

Just going off this tweet, it seems to be user-agent based: https://fixupx.com/endermanch/status/1726605997698068630

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Re:YouTube artificially slows down video load times when usi... by chris_wot on Monday November 20, 2023 @01:59PM (#38352692)

If YouTube are going to go down this path, then perhaps Firefox devs should set the user agent to Chrome for YouTube?

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Re:YouTube artificially slows down video load times when usi... by 36933 on Monday November 20, 2023 @06:54PM (#38356751)

They delayed chrome too. At least for me.

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Re:YouTube artificially slows down video load times when usi... by dmonitor on Monday November 20, 2023 @04:06PM (#38354774)

if it’s anti-adblock, does it run even with premium?

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