PitchPeek

PitchPeek tells you what a recording is actually tuned to. Play something on YouTube, YouTube Music, or Spotify, click the icon, and PitchPeek listens to the tab. It measures how far the music's tonal content sits from the equal-tempered A=440 grid and shows you the reference pitch it settles on — as a needle, a frequency in Hz, and a deviation in cents ("+8¢ sharp", "on the grid"). WHAT IT'S FOR • Playing along with a recording that sounds slightly off, and wanting to know by how much • Checking whether a "432 Hz" upload really is one • Reading tape transfers and older masters, which often drift from modern pitch • Ensembles that tune to something other than 440 CORRECT TO CONCERT PITCH Once a reading settles, one click retunes the tab's audio to your reference in real time, so you can play along without retuning your instrument. Click again to restore the original. Nothing about the source file is changed — only what you hear, and only while you leave it on. SET YOUR OWN REFERENCE Orchestra tunes to 442? Set anything from 430 to 450 Hz. Every reading and every correction re-baselines to it. HOW ACCURATE IS IT Honestly: it's an estimate, and it depends on the material. Instruments produce overtones that don't sit on the equal-tempered grid, so in sparse or overtone-heavy passages those partials can pull the reading a little. Expect roughly ±13 cents on real music. That's enough to separate a 432 Hz recording from a 440 Hz one with confidence and to answer "why does this sound flat?" — it is not a substitute for a hardware tuner on a single sustained note. PRIVACY Everything runs on your device. Audio is analyzed in memory and discarded — never recorded, never uploaded. No analytics, no telemetry, no tracking, and no network requests of any kind. The only things stored are your theme choice and your reference pitch.