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Online Tone Generator

Screenshot of the Online Tone Generator

I made an online tone generator based on the Firefox Audio API HTML5 Web Audio API. It’s basically a large logarithmic slider that allows real-time, smooth frequency changes.


  • Fine-tune the frequency in 1 Hz, 0.01 Hz and 0.001 Hz increments
  • Pick a music note from a list (added Sep 2014, revamped May 2016)
  • Increase/decrease the frequency by one octave (added Aug 2015)
  • Can change the frequency smoothly as you move the slider
  • Keyboard shortcuts (added Aug 2015)
  • Generate a link to a specific tone, so you can share it (added May 2016)
  • Choose sine/square/sawtooth/triangle wave (added Aug 2017)
  • Input frequency as a number (added Aug 2017)
  • Works well on Chrome, Firefox & Safari – including mobile devices (iOS, Android) – requires a browser with support for the Web Audio API.

There are other tone generators on the Web, but they are not as cool (if I do say so myself) and/or they require Java or Flash.

What can you use a tone generator for? You can do a science experiment with resonance, tune a musical instrument, test your new audio system (how low does it go?), test the limits of your hearing (I can hear virtually nothing above 18,000 Hz, even at maximum volume), or figure out your tinnitus frequency to better target therapy.


450 Comments so far

  • David Marshall

    I am 66 years old and have tremor in my hands. Not nice. I have set the tone down to 40 Hz. and it has reduced the tremors nearly down to nothing. I combine with other tones at 432 Hz. I would recommend trying this with anyone that has these sort of issues.
    I play for a couple of hours each day. I will continue to do this as it is very relaxing as well as beneficial.

    Thank you

  • Antonio Dembech

    Will be fantastic to have two different frequencies. One on the left speaker and one on the right speaker. So we can hear the phisics beats.

  • Jes Vesper

    Dear Tomasz,

    Thank you so much for enabling me to listen to 40 herz. It has given me back things I thought I already had lost for ever. I am in the early stages of Huntington’s, a hereditary illness, that has similarities with Alzheimer’s. Listening to your 40 herz for 45 minutes every other day, has lifted the permanent fog in my head; given me back a lot of words; returned my energy; given me back part of my short term memory and cognition. It’s nothing short of a miracle! On top of all that I feel happier.
    So thank you and spread the word!


    • Tomasz P. Szynalski

      That’s great! Thank you for sharing such a positive experience. When did you start listening to 40 Hz?

      • Jes Vesper

        I started a month ago. The fog in my head lifted immediately after one session, the other results grew more slowly. I have to play the piano a lot for my profession, even my playing has become easier.
        I cannot tell you how thankful I am!


  • Jerry Bies

    Which 40 Hz. tone is used Sin, Square, Triangle or Sawtooth for these results?

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