What is a tone generator?
It plays a clean sound at the pitch you choose, from 1 Hz to 20,000 Hz. People use it to test speakers, tune instruments, set up audio gear, or show how sound works.
How to use it
- Turn your volume down. Some tones are louder than they seem.
- Choose a pitch. Type a number, drag the slider, use − and +, or pick a note.
- Choose a shape. Sine is the smoothest. Square, triangle and sawtooth sound brighter.
- Press Play. Change anything while it plays — the sound follows at once.
What everything means
- The picture. Wave shows the shape of the sound; Spectrum shows the pitches in it.
- Frequency. The pitch in hertz (Hz), with − and + beside it and the nearest musical note below.
- Step and slider. How far − and + move the pitch, and a slider for big jumps.
- ×½, ×2 and Pick a note. Go down or up an octave, or choose a note by name.
- Waveform. The shape of the sound: sine, square, triangle or sawtooth.
- Volume, balance and timer. How loud, which side, and when to stop by itself.
- Play and Copy link. Start or stop, and copy a link that opens this exact tone.
Play more than one tone
Tap any of the popular frequencies to add it on top of what is already playing — up to eight at once. Tap it again to stop it, or press Stop all.
Pick a note
Pick a note opens the notes from C2 to C7. Tap one and the tone jumps to it — handy for tuning.
Which waveform should I use?
Sine, unless you want a brighter sound. It is the purest tone, so pitch is easiest to judge.
Can I tune an instrument with this?
Yes. Pick the note you need — 440 Hz is the standard A — use sine, and match your instrument by ear.
Why can’t I hear very low tones?
Small speakers can’t play them. Try headphones or a bigger speaker.
Why does nothing happen when I press Play?
Check that your device is not muted and that the volume slider is not at zero. On an iPhone, also check the silent switch.