YouTube's new anti-adblock measures

Summary

Over the past few months, YouTube has been trying another round of anti-adblock measures. Currently the anti-adblock stuff is being A/B tested, and one of my accounts is in the experimental group. I wrote a filter that partially avoids one of the anti-adblock measures, fake buffering, on uBlock Origin (and Brave browser, since it uses the same filter rules). (It’s already in the default filter lists, you don’t need to manually add the filter.) One thing that people have ran into is “fake buffering”, where videos will take a while to load due to a lot of buffering, but only at the very start of the video (there’s no mid-video fake buffering). As I’ll explain, the fake buffering is 80% of the length of the ads you would’ve seen, so even with fake buffering you’re still saving time using an adblocker. Context InnerTube is YouTube’s first party internal API that the web client and mobile apps use to interact with videos and get details about them. There are some legacy API endpoints that don’t go through InnerTube, but none of those are relevant today. InnerTube endpoints look like https://www.youtube.com/youtubei/. One of those endpoints is /youtubei/v1/player, which the web client calls when you click on a video to get data about the URL and GVS stream URLs. GVS (Google Video Services) is a service that serves video streams for YouTube, Google Drive, and Google Photos. To stream a video from GVS, you need to get a GVS /videoplayback URL from InnerTube (or the Drive/Photos internal API). GVS URLs are signed and have an expiry time (usually 6 hours), so you can’t construct them on your own, you need to get one from InnerTube. One weird thing about GVS is that it isn’t only hosted from Google’s data center: ISPs can put Google Global Cache servers in their infrastructure so that they can serve YouTube videos without needing to send traffic outside the ISP’s network (only public/unlisted YouTube videos are served by GGC; private YT videos and Drive/Photos videos are alway...