Guitar tuner. Pitch, heard on your device.
A chromatic tuner for guitar, bass, ukulele and violin. Your microphone signal is analysed locally with autocorrelation, nothing is ever recorded or uploaded.
A free online tool by Digital HeroesReady to tune
Click below and allow microphone access. Your browser analyses the sound in real time using autocorrelation, nothing is recorded or uploaded.
All pitch detection happens locally in your browser, even offline.
The string nearest to what you’re playing lights up; it turns green when you’re within ±5 cents.
How it hears your pitch
The tuner reads the raw waveform from your microphone and runs autocorrelation, sliding the signal against itself to find its repeating period, with parabolic interpolation for sub-sample precision and a clarity threshold so noise doesn’t fake a reading. It compares the result to the nearest equal-temperament note (using your A4 calibration) and shows the offset in cents. All of it runs about 30 times a second, locally, with no servers involved.
Everything a tuner should do.
- Tune guitar in standard or Drop D with a live needle and a running cents readout.
- Switch to bass, ukulele or violin presets to highlight the correct target strings.
- Use chromatic mode to detect any note from roughly 25 Hz to 2200 Hz.
- Calibrate A4 from 432 to 446 Hz to match an orchestra, a recording session or a period pitch.
- Read the cents offset on a visual gauge that turns green when you’re within 5 cents of pitch.
- Copy your reading, note name, Hz and cents offset, to the clipboard in one click.
Five steps, no cable.
- Open the tuner and click Enable microphone, then allow access when your browser asks.
- Pick your instrument preset, guitar, Drop D, bass, ukulele, violin or chromatic.
- Adjust A4 calibration if you need something other than 440 Hz.
- Play a string and watch the needle and cents display update, tune until the gauge turns green.
- Optionally click Copy reading to save the note name, Hz and cents offset.
Frequently asked questions.
Is the Guitar Tuner free?
Is it private? Is my audio uploaded anywhere?
Does it work offline?
What instruments does it support?
What is A4 calibration and when do I need it?
Why is the reading jumping around?
Published · Last updated .
