Online Tone Generator
This tone generator plays any frequency from 20 Hz to 20 kHz with sine, square, sawtooth or triangle waves. See the nearest musical note, snap to pitch, and try binaural beats — all generated live in your browser.
Left ear plays the base frequency, right ear plays it plus the beat frequency. You only perceive the pulsing through headphones.
Tip: keep the volume gentle. Pure tones — especially high frequencies and the square and sawtooth waves — can sound harsh and are louder than they seem.
How the Online Tone Generator works
A tone generator plays a single, steady frequency so you can test speakers and headphones, find a room's resonance, tune an instrument, check the top of your hearing range, or explore binaural beats. Press Play, then set the pitch with the Hz box or the logarithmic slider — the slider gives the lower frequencies most of its travel so precise pitches are easy to hit. The readout shows the exact frequency and the nearest musical note with its cents deviation, and Snap to note rounds to the closest equal-tempered pitch. Choose a sine wave for a pure tone, or square, sawtooth and triangle for brighter, harmonic-rich colours. Everything runs in your browser with the Web Audio API — no files, no uploads. Need steady background sound instead of a pure tone? Try the White Noise Machine, or play notes on the Online Piano.
Frequently Asked Questions
What frequency range can the tone generator play?
The tone generator plays any frequency from 20 Hz up to 20,000 Hz (20 kHz), which is the full range of typical human hearing. Set the exact value by typing it into the Hz box, or drag the slider — the slider is logarithmic, so the lower, more useful frequencies get most of the travel and it is easy to land on a precise pitch. Most adults stop hearing the very top of the range, so if a high tone is silent your speakers or ears may simply be out of range.
What is the difference between the sine, square, sawtooth and triangle waves?
A sine wave is a single pure frequency with no overtones, so it sounds smooth and clean — best for hearing tests and tuning. Square, sawtooth and triangle waves add harmonics on top of the base frequency, so they sound brighter and buzzier at the same pitch. Square and sawtooth are the harshest; triangle is softer. Start with sine, especially at high volume, and switch waveforms to compare the tone colour.
What are binaural beats and do I need headphones?
Binaural beats play a slightly different frequency in each ear — for example 200 Hz on the left and 206 Hz on the right — and your brain perceives a slow pulsing at the difference (here 6 Hz). You must use headphones for the effect: through speakers the two tones simply mix in the air and you hear one steady beat instead. Turn on the binaural option, set the base frequency and the beat frequency, and keep the volume gentle.
Is it safe to listen to test tones?
At a sensible volume, yes, but pure tones can be deceptively loud and harsh, and high frequencies especially can be uncomfortable. Start with the volume low, avoid long sessions at high levels, and never use tones to test hearing in place of a professional exam. Everything is generated live in your browser — nothing is recorded or uploaded — so you can experiment freely, just protect your ears.
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