FreeHow the tone generator works
Your browser builds the sound wave itself and plays it straight to your speakers, so nothing is downloaded or recorded. The slider is spaced so that each octave takes the same amount of travel, which makes the low end easy to control. Type a number into the frequency box for an exact value.
A sine wave is a single pure pitch. Square, sawtooth and triangle waves add higher harmonics, which sound buzzier and are louder at the same setting, so this page turns them down a little for you.
Things you can do with it
- Find a rattle. Sweep slowly through the low frequencies. Loose panels, desk items and speaker grilles buzz at a particular pitch.
- Check speaker range. Note the lowest and highest tones you can hear clearly. Small speakers often fade out below about 100 Hz.
- Check your hearing range. Most adults stop hearing somewhere between 14 and 17 kHz, and the limit drops with age. This is a curiosity, not a hearing test.
- Tune an instrument. 440 Hz is the standard A above middle C.
Frequently asked questions
Why can't I hear very low or very high tones?
Your speakers or headphones may not be able to play them, or they may be outside your own hearing range. Try headphones for the extremes.
There's no sound on my iPhone.
Check the silent switch on the side of the phone. When it's set to silent, iPhones also mute sound from web pages.
Can I play two tones at once?
Not yet. Open this page in a second tab if you need another tone at the same time.