432 Hz Detector: Is This Song in 432 Hz?
Want to know whether a song is really in 432 Hz? Open the file here and this 432 Hz detector measures the recording's reference pitch: whether its A sits at 440 Hz (the standard), at 432, 442, 444 or at some odd value in between. You get the offset in cents, the nearest common tuning and a confidence score for the reading.
Most common reference pitches
A = 432 Hz is 31.8 cents below the 440 Hz standard; 442 and 444 Hz are 7.9 and 15.7 cents above it.
| Reference A | Where it is used | Difference from 440 Hz |
|---|---|---|
| 440 Hz | International standard (ISO 16): sheet music, keyboards, recordings | 0 cents |
| 442 Hz | Many orchestras | +7.9 cents |
| 444 Hz | Some European orchestras | +15.7 cents |
| 435 Hz | French diapason normal of 1859 | −19.8 cents |
| 432 Hz | Verdi pitch, personal preference | −31.8 cents |
| 430 Hz | Classical music on period instruments | −39.8 cents |
| 415 Hz | Baroque music on period instruments | −101.3 cents (almost 1 semitone) |
How to use it
- Tap Choose an audio file or drop the file onto the page. MP3, M4A, WAV, OGG, FLAC and MP4 videos from your phone all work; on iPhone, the file needs to be in the Files app.
- Wait for the progress bar. Songs up to about 3 minutes are read in full; for longer ones, the detector takes 6 slices of 30 seconds spread across the track.
- Read the A ≈ … Hz value and the offset in cents from 440. The common tunings panel highlights the nearest one and shows the distance to each.
- Check the confidence and the histogram: a narrow peak on one of the lines is a solid reading; a wide hump or two peaks call for caution.
- To retune the file, tap Convert to 440 Hz or Convert to 432 Hz: the pitch shifter opens with the fine tuning already worked out.
Help and explanations
Everything runs in your browser: the audio is decoded and analyzed on your own phone or computer, with no upload. Use it to check a download that claims to be 432 Hz, your band's rehearsal recording, a backing track you want to play along with, or an old recording that sounds slightly off from your keyboard.
How the detector finds the tuning
Every sustained note leaves peaks in the sound's spectrum: the note itself and its harmonics. The detector looks for those peaks between 80 Hz and 2 kHz, measures each frequency to within hundredths of a hertz, and works out how far it is from the nearest note in the A = 440 Hz standard. That difference is measured in cents; a semitone is 100 cents.
If the song was played at 440, the offsets cluster around zero. At 432 Hz every note drops by about 31.8 cents, so the offsets gather near −32. The detector averages them, giving more weight to the stronger peaks, and converts back: A = 440 × 2^(offset ÷ 1200). That is why the histogram shows a peak near the 432 line when a track is in that tuning, and near zero when it is at standard pitch.
What the result cannot tell apart
The method measures where notes fall within a semitone. So a song performed at 432 Hz and one recorded at 440 and later lowered by 32 cents in software give exactly the same result: in the audio they are the same thing. Likewise, 415 Hz, the baroque pitch, is almost exactly a semitone below 440 and shows up as 440; the page tells you when that may be the case.
The reading gets weak when there are few sustained notes: drums on their own, a beat-only track, noise, a voice with very wide vibrato, instruments out of tune with each other, or music that does not use equal temperament, such as gamelan and some Arabic maqams. In those cases the confidence drops and the page explains why instead of making up a number.
Where 440 Hz and 432 Hz come from
Until the 19th century, every city had its own pitch: a 1740 tuning fork associated with Handel is pitched at A = 422.5 Hz, and the one from the Versailles chapel, from 1795, at 390 Hz. In 1859 France fixed A at 435 Hz, the diapason normal, and an 1885 conference in Vienna spread that value across much of Europe. Verdi argued for an A slightly lower than the French one, which is where the nickname Verdi pitch for 432 comes from.
In 1939 an international conference in London recommended A = 440 Hz; ISO adopted it in 1955 and confirmed it in 1975 as the ISO 16 standard. Today 440 is the standard for sheet music, keyboards and recordings, many orchestras tune between 440 and 444 Hz, and period-instrument groups use 415 Hz for baroque and 430 Hz for classical repertoire. There is no scientific evidence that 432 Hz is better for your health or heals anything: it is a matter of taste.
Tips
- A track with 432 Hz in its title is not always in 432: many are the original 440 recording lowered afterwards, and some were never changed at all. The detector shows what is actually in the audio.
- To play along with a recording, tune your instrument to the reference found here: the chromatic tuner lets you choose the reference A, and the 432 Hz tuner opens already set to 432.
- Use the original file if you can, such as WAV, FLAC or a good-quality MP3. Compression does not change the tuning, but low volume and noise leave fewer clear notes to measure.
- Want the tempo and key as well? The BPM and key finder reads the same file, also without uploading anything.
Frequently asked questions
How can I tell if a song is in 432 Hz?
Open the file on this page. If the result puts A close to 432 Hz, with high confidence and the histogram peak on the 432 line, the recording is in 432. If it lands near 440, it is at standard pitch.
What is the difference between 432 Hz and 440 Hz?
At 432, the A vibrates 432 times per second instead of 440, and every other note drops by the same ratio: about 31.8 cents, a third of a semitone. The music sounds slightly lower, but the melody and chords are the same.
Can you tell if a song was recorded in 432 or just converted?
No. A recording made at 432 and a 440 recording lowered by 32 cents sound the same to any measurement. The detector tells you which tuning the track is in, not how it got there.
How do I convert a song to 432 Hz?
After the analysis, tap Convert to 432 Hz: the pitch shifter opens with the fine tuning worked out (440 to 432 is −32 cents). Open the same file there, listen and download it.
Is 432 Hz music better for your health?
There is no solid study showing that 432 Hz has any special effect on the body or mind. Many people simply like the slightly lower sound, and that is reason enough; the healing claims that circulate online are not supported by evidence.
Is Spotify or YouTube music in 432 Hz?
Streaming apps play each track as it was released and do not retune it, and most commercial music is at or near 440 Hz. This page cannot read streams: it needs a file saved on your device, such as an MP3 or a phone video. The file is analyzed right there and nothing is uploaded.
Why did I get 437 Hz or another odd value?
Tape recordings, records played slightly fast or slow, and groups that tune by ear often land between the round values. The page shows the measured value and the nearest common tuning; if nobody changed the speed, the odd number is the band's real tuning.