Tone Generator
A tone generator for exact frequencies: type 440, choose sine, press Generate. White, pink, and brown noise too.
Runs entirely in your browser — your files and text never leave your device.
Synthesised on your device and saved as an uncompressed WAV — nothing is uploaded. Pick a tone with a waveform and frequency, or generate white, pink, or brown noise; set how long it runs, then Generate to preview and download.
How to use
- Leave Source on Tone and type your Frequency (Hz), or switch to Noise and pick White, Pink, or Brown. Then set Duration (s), anywhere from 0.1 to 600.
- Press Generate. The clip lands in the player, and Download saves it as tone.wav.
About this tool
Type a number in hertz and you get exactly that frequency back. The box opens on 440, which is concert A. It accepts anything from 20 up to 20,000 Hz, the usual span quoted for human hearing.
Waveform is a row of four buttons. Sine is the pure one, a single frequency with nothing stacked on top, and it's what you want for a hearing check or a tuning reference. Triangle sits closest to it and only sounds a little brighter. Square and sawtooth pile on harmonics and get buzzy fast.
Switch Source to Noise and the frequency box disappears, because noise doesn't have one. White is flat across the spectrum and sounds like hiss. Pink rolls off about 3 dB per octave, which is why it reads as balanced rather than bright. Brown falls away faster still and comes out as a low rumble.
Nothing streams here. Set Duration (s), press Generate, and the whole clip is rendered up front, then handed to the player below with a Download link beside it. What you get is a mono 16-bit WAV at 44.1 kHz, peaking at about 80 percent of full scale, which leaves a little headroom.
One habit worth keeping: turn the volume down before you press Generate, then bring it up. A five-second sine at 12 kHz arriving through headphones at whatever level your last video was playing is genuinely nasty, and high frequencies are exactly the ones people misjudge.
Good to know
- Duration caps at 600 seconds. Ten minutes of uncompressed mono WAV is already about 53 MB, and for an all-night noise session you're better off generating two or three minutes and looping that in whatever plays it back.
- Only the sine is clean at the top end. Square, triangle, and sawtooth are computed straight from the phase with no band limiting, so their upper harmonics fold back down as false partials once the fundamental climbs past a couple of kHz. Anything you're actually measuring should be a sine.
Things people ask
Which waveform should I use to test a speaker?
Sine, and it isn't close. A sine wave holds one frequency and nothing else, so anything else you hear is the speaker, the room, or your own ears. The other three carry harmonics that muddy the exact thing you're listening for. Keep square and sawtooth for synth-flavoured sound design.
Is 440 here really 440?
Every sample is computed from the number you typed, with no snapping to the nearest musical note, so 440 gives 440 and 437 gives 437. Where exactness stops is playback: your sound card's clock and your speaker both get a vote.
Can I play two tones at once, or sweep between frequencies?
One signal per press. There's no chord, no sweep, and no left-right split for binaural work. Two browser tabs will layer two tones if you need that, though nothing keeps them in phase with each other.
Which noise colour do people actually use for sleep?
Brown, mostly. Its energy sits low and it reads as a distant rumble rather than a hiss, which is easier to ignore for hours. Pink is the usual pick for concentration and for speaker testing, since it spreads roughly equal energy across each octave the way most music does. White is the harshest of the three and the one people give up on first.
How big does a ten-minute file get?
Around 53 MB. The WAV is uncompressed 16-bit mono at 44.1 kHz, which works out to roughly 5.3 MB a minute, and 600 seconds is the ceiling anyway. Generate a couple of minutes and loop it if you want hours of the stuff.
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