432 Hz for YouTube — Real-Time Retuner

Set the reference pitch of any YouTube video, and hear it change instantly. WHY THIS EXISTS A=440 Hz is the ISO standard, and almost nobody obeys it. The Vienna Philharmonic records around 443. Most European orchestras sit at 442. Baroque ensembles play at 415, and French baroque repertoire sometimes at 392. Historical recordings drift with the tape. This maybe annoying to classical enjoyers. So when a retuner multiplies by 432/440 and calls it done, it is guessing. Feed it a recording that actually sits at 443 and you land on 434.9 Hz — not 432. MOST RETUNERS ASSUME. THIS ONE MEASURES. Before it changes anything, this extension listens. It analyses the spectrum of the opening seconds, finds where the partials really fall against the tempered grid, and derives the recording's actual reference. Then it retunes from there. You see the measured value in Hz, the deviation in cents, and a confidence figure. When the material is not tonal enough to measure — speech, solo percussion, applause — it says so and falls back to 440 rather than pretending. No other retuner shows you this, because no other retuner knows. TWO ENGINES Live Shift — a granular pitch shifter built in Web Audio: dual modulated delay lines, Hann-windowed crossfade, 120 ms grains. The pitch moves, the tempo does not. A four-minute movement still lasts four minutes, and the video stays in sync. Around 7 ms of added latency. This is the default, and it is free. Purist — pure resampling. Mathematically perfect, zero artifacts, but playback runs 1.82% slower. For close listening on good headphones, this is the one. It also respects YouTube's own speed controls: at 1.5x you get 1.5x at your chosen reference. WHAT ELSE - Any reference from 400 to 480 Hz, with presets at 415.3, 432 and 444 - Alt+4 toggles instantly, which is what you want for honest A/B comparison - Measured references are cached per video, so a recording is analysed once - Works on watch pages, YouTube Music and Shorts - Survives ads and in-page navigation PRIVATE BY DESIGN Audio is processed inside your browser and never leaves it. No analytics, no telemetry, no tracking, no remote code, no account. The only network request this extension ever makes is when you paste a license key yourself. FREE, AND PRO Free forever: the Live Shift engine at 432 Hz, on youtube.com, with no time limit, no watermark and no signup. That is the full-quality engine, not a crippled preview. Pro, EUR 4.99 once — never a subscription: - the Purist engine - any reference from 400 to 480 Hz, including baroque 415.3 and 444 - measurement of the recording's real tuning - YouTube Music Every install begins with 7 days of Pro. No key, no card, no signup — it simply switches off after a week. THE MATH, IN THE OPEN ratio = target / measured_source. For 432 against a true 440 recording that is 0.981818..., or -31.77 cents. This extension makes no claims about what any tuning does to your body, your mood or your health. It changes the reference pitch of what you are listening to, accurately, and tells you exactly what it did. What you make of that is your business. Not affiliated with, endorsed by, or sponsored by YouTube or Google LLC.