Audio / Tones
Online Tone Generator (Sine, Square, Sweep, 1 Hz–22 kHz)
Generate a pure tone at any frequency from 1 Hz to 22 kHz in sine, square, triangle, or sawtooth waves, see the nearest musical note, and play logarithmic frequency sweeps to test speakers and headphones.
Online Tone Generator (Sine, Square, Sweep, 1 Hz–22 kHz): The browser's audio engine generates the waveform directly, so the frequency is exact: 440 Hz is the A above middle C, and 1,000 Hz sits 21 cents above B5. The slider is logarithmic, giving each octave the same space, and sweeps rise exponentially from the start to the end frequency over the time you set. Runs 100% locally in your browser with zero server file uploads.
- Category
- Everyday tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
Turn your device volume down before you start, then raise it slowly. High-pitched and loud tones can damage hearing and speakers.
A sine wave is a pure tone; square, triangle, and sawtooth waves add harmonics and sound brighter. Sweeps rise on a logarithmic scale, spending the same time on every octave, which is how pitch is heard. Most phone and laptop speakers reproduce little below about 100 Hz, and many people cannot hear above 15 to 17 kHz.
Waveforms
A sine wave is a single frequency. A square wave adds odd harmonics, each weaker in proportion, and sounds hollow and buzzy; a triangle adds odd harmonics that fall off faster, so it sounds softer; a sawtooth adds every harmonic and sounds bright and brassy.
Musical reference
Concert pitch is A4 = 440 Hz, and each semitone up multiplies the frequency by the twelfth root of 2, about 1.0595. To tune by ear, play 440 Hz alongside your instrument, or use the guitar tuner.
How to use it
- Turn your volume down first.
- Set the frequency with the slider, the box, or a preset, and pick a waveform.
- Play the tone, or set a range and play a sweep.
Privacy & limitations
Sound is generated in your browser.
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Frequently asked questions
What is a tone generator for?
Testing speakers and headphones, finding rattles and room resonances, tuning instruments to a reference, checking hearing range, and science lessons on sound.
Why can't I hear very low or very high tones?
Small speakers reproduce little below about 100 Hz, and the upper limit of hearing falls with age; your device's sample rate also caps the highest tone.
Is it safe?
Keep the volume low: pure tones, especially high ones, can be unpleasant and, if loud, damage hearing and tweeters.
Free tool · runs in your browser · no account required