Ask HN: Does anyone else notice YouTube causing 100% CPU usage and stattering?

Hacker News Discussion ↗

Reported Symptoms & Context

  • Multiple users see high CPU usage, stuttering, desynchronised audio, or frozen UIs specifically on YouTube, often on otherwise capable hardware (can game or play local video fine).
  • Problems vary by platform: some see issues on Windows but not macOS, or only in Firefox-based browsers, or only after YouTube has been open for many hours.
  • Some see freezes only when YouTube is in a side window / multi‑monitor, or only in certain views (e.g., “My Videos”, live chat).

Codecs, Hardware Acceleration & Power Use

  • A major theme is AV1 vs H.264 / VP9:
    • If the browser/device lacks hardware decoding for AV1, CPU decoding can peg cores and drain battery.
    • YouTube tends to prefer bandwidth‑efficient codecs (AV1, VP9) even when that shifts power/CPU cost to clients.
  • Users report big gains by:
    • Forcing H.264 (e.g., h264ify / enhanced‑h264ify, or disabling AV1 in browser settings).
    • Checking that AV1/VP9 hardware decode is actually enabled in about:support or browser configuration.

Adblockers & “Intentional” Degradation Debate

  • Some believe slowdowns and interruptions are deliberate punishment for adblock users, citing:
    • The “Experiencing interruptions?” popup wired directly to an ad‑blocker help article.
    • Prior experiments like 5‑second delays, 3‑video limits, and frequent breakage of third‑party clients.
  • Others argue high CPU from adblockers often comes from their own heavy techniques (playlist hammering, proxying, segment removal) and/or that silent CPU spikes are a poor strategy to change user behaviour.
  • There’s broader distrust of “big tech”, countered by appeals to Hanlon’s Razor (incompetence over malice).

YouTube Features & Browser/Driver Issues

  • “Ambient mode” and “stable volume” are repeatedly cited as big CPU hogs; disabling them helps on some devices.
  • Some suspect browser ↔ GPU driver quirks, multi‑GPU setups, or browser‑specific polyfills/user‑agent paths affecting performance.

Workarounds & Alternatives

  • Suggested mitigations: disable ambient mode, tweak AV1 settings in YouTube account, block AV1 in browser, or force H.264 via extensions.
  • Alternatives include playing via mpv/yt‑dlp, Invidious instances, or third‑party mobile clients with integrated ad‑blocking.

Debugging & Profiling

  • For memory/CPU leaks: use Firefox/Chrome devtools (performance and memory snapshots, flame graphs) to identify problematic scripts, though minification/obfuscation makes deeper analysis hard.