Chromatic Tuner

What Is the Chromatic Tuner?

The chromatic tuner is a web-based tool that listens through your computer or mobile device’s microphone to detect pitch in real time. It identifies the musical note, octave, frequency, and tuning deviation (in cents) of any sound source, making it compatible with guitars, pianos, ukuleles, and many other instruments. All audio is processed locally in your browser — nothing is uploaded — ensuring complete privacy.

In addition to its core functionality, this tuner offers:

1. Wide Pitch Detection Range Supports notes from A0 up to G♯9, covering the performance ranges of most musical instruments.

2. Smart Gain Adjustment Automatically adjusts microphone gain when the sound source is farther away, keeping pitch detection stable and accurate.

3. Intuitive Visual Feedback A red-yellow-green indicator shows how close the pitch is to the target note, allowing users to evaluate tuning accuracy at a glance.

This tuner uses the industry-recognized McLeod Pitch Method (MPM) for pitch tracking, combined with FFT processing for improved performance and accuracy. To minimize octave errors — cases where the detected pitch is one or more octaves off — the system incorporates peak validation and harmonic analysis. These errors typically arise from strong overtones or ambiguous period estimation. For a deeper explanation, see this research paper.

What Is 12-Tone Equal Temperament?

12-Tone Equal Temperament (12-TET) is the standard tuning system used in modern Western music. Each octave is divided into 12 equal semitones, meaning the frequency ratio between adjacent notes is constant. This system makes modulation and harmony consistent across keys. More details: Wikipedia: Equal temperament.

Under 12-TET, frequency $f$ and MIDI note number $n$ follow the formula:

Taking n mod 12 yields the corresponding note name:

Notes and Frequency Ranges of Major Instruments

1. Ukulele (4 Strings, GCEA)

Standard tuning (from the string closest to the player’s head to the bottom string):

Note: Ukuleles commonly use high-G tuning, where the 4th string is tuned an octave above the 3rd string’s C.

2. Acoustic Guitar (6 Strings, EADGBE)

Standard tuning (from thickest string to thinnest):

3. Classical Guitar (Same Tuning as Acoustic Guitar)

Standard tuning is identical to steel-string acoustic guitars: E2, A2, D3, G3, B3, E4.

Note: Classical guitars differ in tone, but tuning pitches remain the same.

4. Piano (88 Keys, A0–C8)

A piano’s keys run from low to high, each mapped to a specific pitch:

• Lowest note: A0 (27.50 Hz)
• Middle C: C4 (261.63 Hz)
• Highest note: C8 (4186.01 Hz)

Each octave contains 12 semitones in the repeating pattern: C, C♯, D, D♯, E, F, F♯, G, G♯, A, A♯, B

5. Violin (4 Strings, GDAE)

Standard tuning (from lowest string to highest):

Note: Violin pitch increases by semitone steps as you press along the fingerboard; the open-string notes are as listed.

How to Use the Tuner

1. Start Tuning Click “Start Tuning”. Your browser will ask for microphone permission; grant access to begin real-time pitch detection.

2. Detect Notes and Cents Play each string or key individually. For best accuracy, mute other instruments to avoid interference. The tuner will show the detected note, octave, and deviation in cents. When the pitch is close to the target, the note and meter turn green. Larger deviations appear in yellow or red.

3. Stop Tuning When finished, click “Stop Tuning” to turn off microphone input.

Applications of a Chromatic Tuner

This tuner is useful not only for personal practice but also in various professional scenarios:

• Music Education — Helps students visualize pitch accuracy and understand note relationships.
• Composition & Recording — Ensures consistent tuning during multi-track recording sessions.
• Audio Engineering — Quickly checks whether instruments or electronic sounds match standard pitch.
• Rehearsals & Live Performance — Enables fast, reliable tuning adjustments on the spot.