YouTube Appears to Be Slowing Playback for Firefox Users

A handful of Mozilla Firefox users are reporting a strange five-second delay when launching a YouTube video. According to the same users, playback occurs normally when they switch to Google Chrome, prompting some to believe the issue is browser-related. 

One of the first reports of the delay comes from Reddit user /u/vk6_, who shared a video to the /r/YouTube subreddit Sunday. The video shows /u/vk6_ launching a music video within Firefox. Instead of immediately pulling up the video, YouTube displays a blank loading page for five seconds, then allows the video to begin.

“They’ve added in this artificial 5 second delay here,” /u/vk6_’s caption reads. “Now I’ll change the User-Agent so that YouTube thinks I’m using Chrome.” Once /u/vk6_ makes that swap, the five-second delay disappears.

Similar reports have proliferated across Reddit, Tumblr, and X. Not every Firefox user is experiencing the issue, but for those who are, swapping browsers—or changing the browser’s user agent—gets rid of the delay entirely. Another Reddit user, /u/paintboth1234, even dug into YouTube’s desktop client to find a piece of “setTimeout” JavaScript code that reportedly initiates the pause. 

Credit: /u/paintboth1234

Has YouTube become a pawn in the browser wars? Perhaps. YouTube recently expanded its anti-ad blocker “experiment” from back in May to push users to Premium. Firefox—and the uBlock Origin browser extension—quickly emerged as an alternative to sitting through ads or paying $14 per month for a Premium membership. It wouldn’t be surprising whatsoever if the folks at YouTube weren’t thrilled about that, and because Google owns YouTube, it makes sense that YouTube would push users to Chrome—even if doing so involved a dirty trick like this one.

In a statement to Android Authority, YouTube denies the delay’s connection to web browsers. “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,” a spokesperson said Tuesday. “Users who have ad blockers installed may experience suboptimal viewing, regardless of the browser they are using.” 

But while this offers a touch of context, it doesn’t clarify why the issue disappears once users switch to Chrome. Worse, Android Authority adds that “users who experience the delay are advised to either allow ads for YouTube or subscribe to YouTube Premium.” This “advice” appears to come from YouTube’s spokesperson, bringing us right back to square one.