Pitch Detector

How to detect a pitch in three steps

It works in your browser, with nothing to install and no account.

1. 1

   Pick the microphone or a file

   Microphone reads live as you play. Audio file takes a recording you already have: common formats up to 100 MB, with the first 5 minutes analysed.

2. 2

   Make one clear sound

   Press Start, allow the microphone and hold one note for a second or two, close to the mic. A plucked string, a sung vowel, a whistle, a flute or a tuning fork all work. Two notes at once do not.

3. 3

   Read the note, the hertz and the cents

   The big letter is the nearest note, the number under it is the frequency, and the needle shows how far off you are. Inside 5 cents the needle turns green. Press Hold to freeze the reading and write it down.

Reading the result: note, hertz and cents

Reference notes and their frequencies

A few notes you are likely to check, with A4 at 440 Hz.

Microphone or audio file?

Both use the same detector. They answer different questions.

• Microphone: what is this note right now?

  Use it to name a note on an instrument, check a string, find the pitch of a hum or a beep in the room. The graph keeps the last 15 seconds, so you can see a slide or a wobble as a line.

• Audio file: which notes are in this recording?

  Use it for a sung melody, a solo line or a sample. You get the pitch line through the file, the most common note, the median frequency and the lowest and highest note.

• The note list

  File mode cuts the pitch line into notes and lists each one with its start time, frequency and length. Notes shorter than 0.15 seconds are left out, so fast ornaments may be missing.

• The CSV

  The download holds the whole track, one row every 0.05 seconds: time, frequency, note and cents. Open it in a spreadsheet to plot a melody or measure vibrato.

What it cannot do

The detector looks for one repeating wave. These are the cases where there is none, or more than one.

• Chords and several notes at once

  Two or more notes sounding together give no clear pitch, or the detector follows whichever note is loudest. Play the notes of a chord one at a time to name them.

• Full songs and mixes

  A finished track has drums, bass, chords and a voice on top of each other. The reading jumps or goes blank. The key and the tempo of a whole song need different methods.

• Very low and very high sounds

  It names notes from A1 (55 Hz) to C7 (2,093 Hz). The lowest string of a bass guitar, E1 at 41.2 Hz, is below that: it shows no clear pitch, or reads one octave up when the microphone misses the fundamental.

• Noise, drums and speech consonants

  Hiss, claps, cymbals and the s or t of speech have no pitch, so the display says no clear pitch. That is the correct answer and not a fault.

The reference pitch and the note names

When the reading jumps

A jumping note usually has one of these causes.

• An octave too high or too low

  Some sounds carry a stronger overtone than fundamental, and a small speaker or phone mic can drop the lowest part altogether. Move closer, play a little louder, or check the graph: the true note is usually the line it spends the most time on.

• Flickering between two notes

  A sound close to the 50 cent border sits between two names. Look at the hertz value and the needle. The note list in file mode holds on to a note until the pitch is clearly on the next one.

• Nothing shows at all

  The sound is too quiet, too short or too noisy. Hold the note for a full second near the mic, and turn off fans and music in the room.