Signal generator · 1 Hz – 20 kHz
Online Tone Generator
Enter a frequency and press play. The tone is synthesised live by your browser with the Web Audio API - no plugin, no account, no upload - and stops the moment you tell it to. Sine, square, sawtooth and triangle waveforms, exact frequency entry, and a 16-bit WAV export of whatever you hear.
Pure tones at high volume can damage hearing and speakers. Start with the header level low, especially before testing high frequencies or subwoofer settings. The limiter prevents digital clipping, not loud playback.
↑ ↓ nudge ±1 Hz · Shift + arrows ±10 Hz · Enter play · Esc stop
Ready. Press play to sound the tone.
Wavelength
0.78 m
Period
2.273 ms
MIDI
69
Octave
4
Nearest note
A4 · 440 Hz
Deviation
exact
| Waveform | Harmonics | Sound & typical use |
|---|---|---|
| Sine | None | The purest tone. Calibration, hearing tests, subwoofer and room measurements. |
| Square | Odd only (1/n) | Hollow and buzzy. Retro game sounds, logic and clock testing. |
| Sawtooth | All (1/n) | Bright, string-like. Synthesiser strings and brass. |
| Triangle | Odd only (1/n²) | Mellow and soft. Flute-like leads, gentle test tones. |
A pure sine wave contains energy at exactly one frequency. The other three waveforms add harmonics at whole multiples of the fundamental, which is why they sound brighter - and why they read as a comb of peaks in the spectrum display above.
How accurate is the tone?
The oscillator is generated by your browser’s Web Audio API at the device sample rate (typically 44.1 or 48 kHz). Frequency accuracy is limited only by the crystal in your sound card, which is normally better than 0.01%. The readout shows the exact frequency you entered plus the nearest musical note and the deviation in cents.
Why can’t I hear anything?
Check three things in order: the site level slider in the header, your system volume and the correct output device. Then check the frequency - anything above roughly 16 kHz is inaudible to most adults, and below about 30 Hz you will feel it more than hear it unless your speakers can reproduce it. Headphones make sub-bass and high frequencies far easier to hear.
Can I download the tone as a file?
Yes. The Save button renders the exact tone you have configured, in your browser, into a 16-bit PCM WAV file at 44.1 kHz - 1, 5, 10 or 30 seconds long - and downloads it. Nothing is uploaded; the file is built locally and works in any audio software.
How do I share a specific tone?
Every setting is in the URL. https://soundgenerator.app/?freq=432 plays 432 Hz on load, and https://soundgenerator.app/?freq=1000&waveform=square pre-selects the square wave as well. Use the Copy link button to grab the URL for the current settings.
Setting an exact frequency
Type the number you want (whole hertz or decimals, for example 146.83) and press
Enter. While a tone is playing, editing the field retunes it live - no need to stop
and start. The arrow keys step by 1 Hz, or by 10 Hz with Shift held, which is the
fastest way to walk a frequency band by ear.
Working with the slider
The slider is logarithmic, matching how we hear: equal slider distances are equal musical intervals. The
lower half of the travel covers 20 Hz – 640 Hz, which is why small movements down there matter. The
÷2 and ×2 buttons jump exactly one octave, and the note keys play equal-tempered
pitches directly.
Saving a tone
Save WAV renders the current frequency and waveform offline in your browser and downloads a 16-bit PCM file at 44.1 kHz, starting and ending on a zero crossing so there are no clicks at the edges. Use it when you need a file for a phone, a test rig, a DAW or a device that will not run Web Audio.
Sharing an exact tone
The address bar is the preset store. ?freq=432 loads 432 Hz,
?waveform=square pre-selects the square wave, and they combine:
?freq=1000&waveform=sawtooth. Copy link builds that URL for whatever you
have set right now.
Multiple Tone Generator
Run up to eight independent oscillators with per-voice frequency, waveform, level and stereo pan.
Frequency Sweep Generator
Linear or logarithmic sweeps between any two frequencies, with start/end levels and optional hold.
Noise Generator
White, pink and brown noise with band shaping - for masking, calibrating and testing.
Instrument Tuning Tones
Reference pitches for guitar, bass, ukulele, violin, cello, mandolin, banjo and viola.
Online Hearing Test
Step through audiometric frequencies from 125 Hz to 20 kHz and log what you can hear.
Subwoofer Test Tones
Low-frequency test signals from 16 Hz up, plus sweep tools for finding room and driver limits.