Play a pure tone at any frequency from 1 Hz to 20 kHz, switch between sine, square, sawtooth and triangle waves, or sweep a range to hunt for resonances. The sound is made in your browser and nothing is uploaded.
Online Tone Generator
Play a pure tone at any frequency from 1 Hz to 20 kHz, switch between sine, square, sawtooth and triangle waves, or sweep a range to hunt for resonances. The sound is made in your browser and nothing is uploaded.
The tone is generated on your device while it plays, and nothing is recorded, saved as audio or sent anywhere. Your frequency, waveform, channel and sweep choices are remembered in this browser only; the volume is not, so every visit starts quiet.
The Online Tone Generator plays a steady tone at any frequency from 1 Hz to 20 kHz. Type a number such as 440 or 1.5k, or a note name such as A4 or C#3, drag a logarithmic slider that gives every octave the same width, or step the pitch by 1 Hz, 10 Hz, a semitone or an octave. Under the number it shows the nearest note, how many cents sharp or flat the pitch is, and the frequency band it falls in. Pick a sine, square, sawtooth or triangle wave, send it to the left or right side only, and watch it on a live oscilloscope. The Sweep tab glides between two frequencies, once or on repeat. The volume starts at 15 percent and every start, stop and change is faded, so nothing clicks. The sound is made on your device.
Features
Any frequency from 1 Hz to 20 kHz, typed as 440, 1.5k, 2000 Hz or a note name such as A4 or C#3
A logarithmic slider from 20 Hz to 20 kHz, plus steps of 1 Hz, 10 Hz, one semitone and one octave
The nearest note, its offset in cents and the frequency band, from sub-bass to brilliance, under the number
Sine, square, sawtooth and triangle waves, with the square trimmed by 3 dB so it is no louder than the sine
Left, right or both channels, to check which side each speaker or earbud plays
A sweep from any start to any end frequency over 1 to 120 seconds, logarithmic or linear, once or repeating
A live oscilloscope of the sound, with a still preview of the wave for people who prefer reduced motion
Quiet by default: 15 percent volume on an audio taper, 40 ms fades, warnings for loud or very high tones and an optional auto-stop timer
How to use the Tone Generator
Type a frequency or note, drag the slider or press a preset such as 440 Hz or 1 kHz reference
Keep the volume low, pick a waveform and choose both, left or right channel
Press Play or the space bar, change the pitch while it sounds and press Stop when you are done
Open the Sweep tab to glide between two frequencies and listen for a rattle, a buzz or a sudden peak in loudness
Example
Input
Tone tab · type A4 · waveform Sine · channel Both · volume 15 %
Note names use equal temperament with A4 at 440 Hz, so typing 432 instead reads A4, −32 cents.
Common errors & troubleshooting
I press Play and hear nothing. — Check that the tab and your device are not muted and that the volume slider is above zero. Browsers allow sound only after a click or key press, and Play counts. On an iPhone, also check the silent switch.
Low tones are silent or only rattle. — Phone and laptop speakers play very little below about 100 Hz, and nothing below 20 Hz can be heard at all. Use headphones or a larger speaker, and do not turn the volume up to compensate, because that can damage a speaker.
I cannot hear the 15 kHz or 18 kHz tone. — Hearing for high pitches fades with age, and many adults hear little above 16 kHz. Some speakers and earbuds also play it only faintly. That is normal and does not mean the tone is missing.
I want to download the tone as an audio file. — The generator makes the sound live and cannot save it as a file. To capture it, record your device's audio with a screen recorder that includes system sound.
Frequently asked questions
How does the Online Tone Generator make a tone in the browser?
The browser's Web Audio engine runs an oscillator that works out the wave sample by sample, usually 44,100 or 48,000 times a second, and sends it to your speakers. No audio file is downloaded or streamed, so the pitch is exact and the tone starts the moment you press Play.
What does each waveform sound like on the Online Tone Generator?
A sine is a pure, smooth tone with no overtones. A square wave sounds hollow and buzzy because it adds only odd harmonics. A sawtooth is bright and rasping and contains every harmonic, and a triangle is a softer, more muted cousin of the square. All four share the same fundamental, so they sound like one note in different voices.
Why can't I hear very high or very low tones on the Online Tone Generator?
Your ears, your speakers and the volume all set limits. People hear roughly 20 Hz to 20 kHz when young, and the top end shrinks with age. Small speakers and earbuds play almost nothing below 100 Hz or so. Start with a 1 kHz tone to check your setup, try headphones, then move towards the extremes.
Is the Online Tone Generator safe for my speakers and ears?
It starts at 15 percent volume on an audio taper and fades every start and stop, and it warns above 70 percent or above 12 kHz. Loud or very high tones can tire your hearing and overdrive small speakers, so set your device volume low first and raise it slowly. Never turn up a tone below 20 Hz to hear it, and remember that high pitches can disturb pets.
What is the difference between 440 Hz and 432 Hz on the Online Tone Generator?
440 Hz is the modern concert pitch for the note A above middle C, the reference orchestras and tuners use. 432 Hz is a slightly lower alternative that some musicians choose by preference. It sits about 32 cents flat of A4, a third of a semitone, and the readout shows that when you switch between the two presets.
How do I use the Online Tone Generator's sweep to find a resonance?
Open the Sweep tab, pick a range such as Bass 20–200 Hz, set 20 to 60 seconds, switch on Repeat and press Play. Listen for a frequency where something buzzes, rattles or suddenly gets louder, such as a shelf, a panel or a room mode. Note the frequency on screen at that moment, then play a plain tone there to confirm it.
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