Chromatic Tuner (Online Tuner)

A chromatic tuner shows the nearest note, from any of the twelve, and how many cents you are above or below it, so it works for guitar, bass, violin, ukulele, wind instruments, piano strings and singing. Tune live with your microphone, check a recording to see which notes were sung or played over time, or play an exact reference note to tune by ear. Sound is analysed in your browser and never recorded or uploaded.

How to use this tool

1. Choose "Tune live with the microphone" and press Calculate; allow the microphone when asked.
2. Play or sing one note: the big letter is the nearest note, the bar shows cents flat (left) or sharp (right); green means within ±5 cents.
3. To check a recording, choose a file: you get the main note and a table of the notes over time.
4. To tune by ear, choose "Play a reference note", type a note such as E2 or A4, and press Calculate.

Formula

f = A4 × 2^((n − 69) ÷ 12) · cents = 1200 × log2(f_measured ÷ f_note)

n is the MIDI note number (A4 = 69, middle C = 60). The pitch is found with the YIN method, which compares the sound with delayed copies of itself and takes the best-matching delay as the period, refined between samples. The tuner reads 50 to 2000 Hz (G♯1 to B6); notes outside that range give "no clear note" rather than a wrong reading. The live display uses the median of the last five readings so it does not jitter.

Example

With A4 = 440 Hz, the note E4 is 440 × 2^((64 − 69) ÷ 12) = 329.63 Hz. If you play 332.0 Hz, that is 1200 × log2(332.0 ÷ 329.63) = +12 cents: slightly sharp, so lower the pitch a little.