Online pitch detector — free pitch detection for voice & instruments

What is a pitch detector?

A pitch detector is an online tool that listens to your voice or instrument through your microphone and identifies the musical pitch of the sound you produce. Pitch refers to how high or low a sound is — high-pitched sounds like a whistle have a high frequency (measured in Hertz, or Hz), while low-pitched sounds like a bass drum have a low frequency. This pitch detector uses autocorrelation-based pitch detection to analyze your audio signal in real time, displaying the detected musical note (C, C#, D, etc.), octave number, exact frequency in Hz, and tuning accuracy in cents. It works with most instruments including guitar, violin, piano, and vocals. Unlike instrument-specific tuners that only compare against fixed target notes, this general-purpose pitch detector identifies any pitch within the audible range — making it ideal for singers, vocal practice, ear training, and any instrument tuning.

Online pitch detector — pitch detection features

A browser-based pitch detector with real-time note identification, frequency measurement, cents accuracy display, and a visual radial gauge.

1. Real-time pitch detection via autocorrelation: The pitch detector uses an autocorrelation algorithm running on the Web Audio API to accurately measure the fundamental frequency of your voice or instrument. The algorithm works by finding repeating patterns in the audio waveform, giving precise pitch readings from 50 Hz to 2000 Hz — covering the full vocal range and most instruments.
2. Musical note display with octave number: Detected pitch is instantly converted to a musical note name (C, C#, D, through B) with the correct octave (e.g., C3, A4, G5). The 12-note radial gauge shows all chromatic notes with your detected note highlighted in blue, making it easy to see which note you are producing at a glance.
3. Exact frequency in Hz and tuning cents display: See your pitch as both a precise frequency (e.g., 440.0 Hz) and tuning accuracy in cents. Green cents (5 or less) indicate you are in tune; yellow/orange cents indicate you are sharp or flat. This is ideal for vocal practice, instrument tuning, and ear training.
4. Visual radial gauge with needle indicator: A full 360-degree radial gauge displays all 12 musical notes around a circle. A red needle points to your current pitch, and colored dots show exactly where you land relative to the note — whether dead center (in tune) or slightly sharp/flat.
5. Works with voice, guitar, violin, piano, and more: This pitch detector works with any melodic sound source. Sing or hum into your microphone to check your vocal pitch. Play guitar, violin, piano, flute, ukulele, or any other instrument. Built-in guitar tuning reference frequencies help you quickly tune each string to the correct note.
6. 100% private — all processing runs locally: Your privacy is guaranteed. All pitch detection runs entirely in your browser using the Web Audio API. No audio is recorded, stored, or sent to any server. The pitch detector works offline once the page is loaded.

How to use the pitch detector — step-by-step guide

A simple step-by-step process for using this free online pitch detector to identify musical notes and check tuning.

1. 1. Click Start Pitch Detection and allow microphone access: Click the Start button and allow your browser to access your microphone when prompted. The pitch detector needs microphone permission to analyze audio — no audio is recorded or saved.
2. 2. Sing, hum, or play an instrument into your microphone: Produce a clear, sustained note into your microphone. The pitch detector works best with a steady tone — avoid vibrato or rapidly changing notes for the most accurate reading. Get close to the mic and avoid background noise.
3. 3. Read the detected note, frequency, and tuning accuracy: Watch the radial gauge — the red needle points to your detected note and the center displays the note name with octave (e.g., A4) and exact frequency in Hz. The cents display shows tuning accuracy: green (5 cents or less) means you are perfectly in tune.

Pitch detector tips — get the most accurate pitch readings

Tips and best practices for getting accurate pitch detection results with this online pitch detector.

1. Produce a clear, sustained note for best accuracy: The autocorrelation pitch detection algorithm works best with steady, sustained tones. Hold a single note without vibrato for at least half a second to get a stable reading. Rapidly changing notes or vibrato can cause the needle to jump between adjacent notes.
2. Reduce background noise: Background noise, fans, air conditioning, and other ambient sounds can interfere with pitch detection. Use the pitch detector in a quiet environment for the most accurate results. If using a laptop, position it so fan noise does not reach the microphone.
3. Position the microphone correctly: For vocal pitch detection, position yourself 6-12 inches from the microphone. For acoustic instruments like guitar or violin, position the microphone 6-12 inches from the sound hole or f-holes. Avoid placing the microphone directly in front of loud amplifiers.
4. Use the guitar tuning reference chart: This pitch detector includes a built-in guitar tuning reference showing the standard frequencies for each string: E2 (82.4 Hz), A2 (110 Hz), D3 (146.8 Hz), G3 (196 Hz), B3 (246.9 Hz), E4 (329.6 Hz). Use these as target frequencies when tuning your guitar.
5. Understand the cents display: Cents measure fine tuning accuracy. One semitone equals 100 cents. Green (5 cents or less) = in tune. Yellow (5-15 cents) = slightly off. More than 15 cents = sharp or flat by a noticeable amount. For instrument tuning, aim for 5 cents or less.
6. Microphone quality matters: While this pitch detector works with built-in laptop and phone microphones, an external USB microphone or audio interface will provide cleaner signals and more accurate pitch detection. Built-in microphones may pick up more room noise and have limited frequency response.

Frequently Asked Questions

Have questions? We have answers.

Related tools

More tools from Audio Tools.

• Mic Test

  Mic test online—check your microphone with live waveform and volume level.

• Sound Test

  Sound test online—check your speakers, test left/right channels, and verify stereo balance.

• Keyboard Test

  Keyboard test online—check every key. Detect unresponsive, stuck, or ghosting keys.

• Webcam Test

  Webcam test online—test your webcam for free. Check camera resolution, frame rate, megapixels, and image quality.

• Mouse Tester

  Mouse test online—check all buttons and scroll wheel. Detect double-click issues.

• Controller Tester

  Controller tester online—test every button, thumbstick, trigger, and vibration motor.