The 29a Chromatic Tuner is a web based application to help you tune your instrument.


Click on 'Start' to start the tuner. You will then need to allow it to access your microphone (or audio interface). The dialog to do that will usually pop up in the top left corner of the browser window.

You can pause the tuner by clicking on the note display.

Supported Instruments

The tuner is chromatic and and works form 30 to 2000 Hz so it should be suitable for use with most instruments. It has been sucsessfully tested with:

  • Acoustic Guitars (via line and microphone)
  • Electric Guitars (via line and microphone)
  • Electric Bass, and extended range guitars (via line)

That's all the instruments I had around the house. Had success with something different? Let me know! :)


Clean Direct Signal

Given a clean direct signal the tuner is typically accurate to less than 1 cent. It should be good enough for demanding tasks like setting intonation and likely exceed the Just-noticeable difference in Pitch.

Noisy Signal from a Microphone

When the signal is coming from a more noisy source like a microphone the accuracy becomes significantly worse. Expect to be off by 5 cent or more.


The tuner struggles in the presence of noise, reverb or if the harmonics are very powerful compared to the fundamental signal.

If you can't tune from a direct signal from a pickup (piezo or magnetic), try to keep the microphone as close to the instrument as possible. If you are using a notebook you can try psyically touching the device with your instrument while tuning. If low notes are not recognized try to play a harmonic or a octave higher.

Technical Details

If you are interested in some of the more technical details please read the article I made myself a guitar tuner on my website.


You can find my contact details on 29a.ch/about.

Chromatic Tuner

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