Frequency generator (audio tone)
Generate tones from 20 Hz to 20,000 Hz in the browser, with sine, square, triangle or sawtooth waves, to test speakers and your hearing.
How to useFrequency generator
Available in: 
Frequency generator (audio tone): what it is for
Choose the frequency with the slider, type the value in Hz or use the shortcuts and play the tone in the browser. The tool shows the nearest musical note and the difference in cents.
It has four waveforms, octave controls and a sweep from 20 Hz to 20 kHz in 20 seconds to test speakers and how high you can hear.
How to use
- Choose the frequency and waveform.
- Adjust the volume, starting low.
- Play or run the sweep.
When to use it
- Testing speakers, headphones and subwoofers.
- Running a high-frequency hearing test.
- Generating a reference note for tuning.
Frequently asked questions
What is a frequency generator for?
To test speakers and subwoofers, find rattles and vibrations, tune instruments with a reference note and test how high you can hear.
How high can an adult hear?
Human hearing goes from about 20 Hz to 20,000 Hz, but the upper limit drops with age. Many adults cannot hear above 15,000 to 17,000 Hz.
Is it safe?
Start with the volume low, especially with headphones. Loud high-pitched tones can be uncomfortable and tire your hearing.
Is it really free?
Yes, 100% free. No sign-up, no subscription and no usage limits. All Tools123 tools are free and run right in your browser.