If you are a Firefox user and visit YouTube frequently, you have probably noticed that the site's overall performance in that browser is not the best, while in Google Chrome it seems to fly. A Mozilla administrator said on Twitter that page loading of YouTube in Firefox can be up to five times slower, and as a solution shared an extension that reverts YouTube to a more classic state. We would like to add to that extension another one that changes the compression standard during streaming, making better use of hardware acceleration.
It all started when Chris Peterson, technical manager at Mozilla, shared a tweet indicating that page loading of YouTube in both Firefox and Edge is five times slower when compared to Google Chrome. His first hypothesis was that YouTube uses Shadow DOM v0, an obsolete API found only in Chrome. Thanks to Alex Russell's additional debugging, the cause of the performance loss seems to be the Shady DOM of Project Polymer, negatively affecting everything that is non-Chrome. That's how we came to our mission, which is how to improve YouTube speed in Firefox. Peterson himself shared the first resource:
https://twitter.com/cpeterso/status/1021626510296285185
The First Extension: YouTube Classic
It is a small extension called YouTube Classic, last updated on May 7. Its description only says that it "restores the classic version of YouTube", but in reality what it does is present the pre-Polymer edition of YouTube that older browsers receive, for example, Internet Explorer 11.
The extension does not require any advanced configuration or anything like that, although I recommend restarting Firefox just in case. YouTube will return to its previous edition, with more compact menus and a direct list of subscriptions. Personally I believe the performance improvement is real, and all of YouTube responds faster with the extension.
The Second Extension: H264ify
Our second suggestion to improve YouTube speed in Firefox is to install the H264ify extension, which forces YouTube to offer H.264 streams instead of VP8 or VP9. Although Google has plenty of reasons to favor VP9 (bandwidth savings being one of them), hardware acceleration and playback smoothness at higher resolutions tend to be more complete with H.264. Many users have even reported greater energy efficiency on laptops with H264ify, so we recommend giving it a try. Ideally, Google would fix all YouTube issues, but the combination of YouTube Classic and H264ify is a good shortcut.
