Reports of YouTube freezing browsers and consuming enormous amounts of RAM began spreading across Reddit and browser forums late last week, with developers now pointing to a bug in the platform's interface code that may be trapping browsers in an endless layout recalculation loop. What's emerging is that there is a runaway interface bug buried inside the platform's video controls.
Users across multiple browsers, including Firefox, Brave, and Microsoft Edge, have described videos stuttering, tabs becoming unresponsive, and systems slowing to a crawl while watching YouTube. Some users reported the individual YouTube tabs consuming more than 7GB of RAM.
Following investigations, reportsMozilla's emerging from Mozilla’s open-source bug-tracking system, Bugzilla, suggest YouTube's frontend interface logic is the main culprit. Developers investigating the issue appear to have narrowed the problem down to the flexible menu container located directly beneath the video player — the section containing controls such as Like, Dislike, Share, and other interaction buttons.
Button peek-a-boo loop
According to comments related to the investigation, the interface repeatedly checks whether all buttons fit within the available horizontal space. If the controls overflow, the system hides one of the buttons to free space. However, hiding the button changes the container's width, immediately creating a new problem.
Once the button disappears, the available width appears enough for the interface to believe there is room again, causing the hidden button to reappear. The buttons then overflow once more, forcing the interface to hide the button again. The cycle repeats continuously at extremely high speeds.
While the visual behavior itself may appear minor, the consequences inside the browser can be far more significant. Modern browsers constantly recalculate page layouts whenever interface elements change size or position. If a webpage repeatedly triggers those recalculations thousands of times per second, the browser can become trapped in what developers often call layout thrashing or a reflow loop.
That forces the browser to continuously recompute layout geometry, redraw interface elements, and update rendering states, rapidly consuming CPU resources and memory. A user shared screenshots on Reddit showing CPU cores pinned near maximum utilization while YouTube tabs became nearly unresponsive. Others reported browser-wide slowdowns severe enough to temporarily freeze entire systems.
Mozilla developers are reportedly still investigating the issue, though no broadly confirmed fix appears to exist yet. The fact that both Firefox-based and Chromium-based browsers appear to experience similar problems further supports the suspicion that the issue may originate primarily with YouTube. For now, the exact root cause remains unofficial; neither Google nor YouTube has publicly confirmed the source of the problem.
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