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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.


400 Comments so far

  • Jim Busse

    Thanks you. This is great work.

    I had to sell my HP sig gen when I moved to Singapore (220V here) and wish this generator had a sweep frequency capability. It would be nice to use the slider to set the min frequency, have another button to set the max frequency, and a start/stop button to allow free-running repetition.

    This one is helping me out, thanks!

  • Dale

    Hi. We’re trying out your tone generator for my wife, who has mild memory loss. Luckily, we were given a powered subwoofer made for computer output. Thanks so much! Wish us luck.

    What we’re missing is the nuances of its use. I’m hoping you can supply them or recommend an authoritative info source. We have the woofer in a corner, but other issues include:
    Which wave form is best? We’re using sine right now.
    Do headphones work better than an open-air speaker? Self-canceling headphones?
    Can the tone be effective in a space with other noise—such as voices, TV or clatter—or must it be the sole sound?
    The sound freaks out our cat a little, at least now, as we start. Will it hurt pets, physically, emotionally or mentally?

    Hope you can help. Keep up the good work!

  • Steen Oluf Karlsen

    Hello Signalski guy(s)- Steen ok from the Tech High School in Thy Danmark here!
    Two teenagers in my class have built an audio Frequency analyser – with an fft algorithm from Steve Smiths online resource book (hereby recommended!) We have tested and tested again the ability to – get the different ingredients of the “slush ice audio” back in their respective boxes as one of the boys put it! Sometimes I have been wondering how good the precision is for the frequency content in the signalsky generator? Especially when our equipment disagreed… Will the frequency of the generator be affected by the clock freq of the PC that generates the signal? How can you control the frequency across the many different processor types / platforms?

    • Tomasz P. Szynalski

      The processor doesn’t affect the frequency. In electronic audio, the analog audio signal is generated by a DAC which has its own clock. I would not expect significant deviations, but I have not tested it (not even sure how?). FFTs, on the other hand, are not very precise because of the need to separate the signal into frequency bands.

  • Aden Gusic

    Hey There!

    Thanks so much for creating this site! its is so good, i really like this tone generator.
    i like pranking my friends in class.

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