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.