Online tone and frequency generator
Play a continuous tone at the exact frequency you need, from 20 Hz to 2,000 Hz. Drag the slider, type a frequency or pick a preset such as A4 at 440 Hz, and choose a sine, triangle, square or sawtooth wave.
Use it as a tuning reference, to test speakers and headphones, or to hear how waveforms differ. The nearest musical note and its offset in cents are shown for every frequency.
How to use the tone generator
- Set the frequency with the slider, which moves on a musical log scale, or type an exact value.
- Pick a waveform: sine is pure, triangle soft, square hollow and sawtooth bright.
- Start at a low volume, then press Play tone. Changes apply while it plays.
Frequently asked questions
What frequency is A4?
A4, the A above middle C, is 440 Hz in standard tuning. Some musicians prefer 432 Hz; both are presets.
Which waveform should I use for tuning?
A sine or triangle wave is easiest to tune against because it has few or no overtones.
Is a tone generator safe for my ears and speakers?
Keep the volume low, especially with headphones and very low or high frequencies, and stop the tone if it is uncomfortable.