Pick a frequency, waveform and channel, then press Play. Great for testing headphones, speakers, subwoofers and your hearing.
Start with the volume low, especially on headphones. Loud, continuous high tones tire your ears and can damage speakers.
440 Hz
A4
Presets
Frequency sweep
Sound is generated in your browser with the Web Audio API. Nothing is downloaded or uploaded.
Keep your device volume and the page’s volume control low before playing, especially with headphones.
Drag the slider (logarithmic, 20 Hz to 20 kHz), type an exact value in Hz or tap a preset such as 440 Hz or 1 kHz.
Use a sine wave for clean tests. Pick Left, Right or Both to check each side of your headphones or speakers.
Press Play for a steady tone, or set start, end and duration and press Start sweep to glide through the frequencies.
A tone generator produces a pure, steady frequency. Use it to find how low your subwoofer really goes, track down rattles and resonances in a car or room, check that both sides of your headphones play at the same level, or tune instruments to A = 440 Hz.
A sweep glides continuously through the range. In a 20 Hz to 20 kHz sweep, notice when the sound disappears: that marks the limit of your speaker or your hearing. Most adults stop hearing somewhere between 14 and 17 kHz, and the limit drops with age.
A sine wave contains a single frequency and is best for measurements. Square, sawtooth and triangle waves add harmonics and sound harsher; the page automatically lowers their level because they carry more energy. Still, always start with the volume low.
Avoid long, loud high-pitched tones: they tire your ears and can damage tweeters. Very low bass at high volume can also over-drive small speaker cones.
Tap the 440 Hz preset or type 440 in the frequency box and press Play.
From 20 Hz to 20,000 Hz (20 kHz), the range of human hearing. The slider is logarithmic so low frequencies are easy to set.
Under Channel, choose Left or Right and the tone plays on that side only. For a full left/right check, also try the Audio Test.
Run a 20 Hz to 20 kHz sweep at low volume and note where you stop hearing it. Treat it as a rough guide: the result also depends on your headphones.
At high volume, yes, especially continuous high tones or very low bass. Start low and raise the volume gradually.
Yes. Open the page in your phone’s browser, make sure silent mode is off and press Play.
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