Online Tone Generator

Play a pure tone at any frequency with a choice of waveforms.

Everything runs in your browser. No audio is ever uploaded.

440Hz
Hz
Drag the slider for a coarse sweep, or type an exact frequency in Hz. Arrow keys move the slider. Hold Shift for 1 Hz steps, or Ctrl for 0.1 Hz steps.
Quick frequencies

Settings

Mode
Waveform
-12 dB
0
Download as WAV
File length

The file is rendered in your browser with the current waveform, volume and balance. A sweep is exported over its own duration.

Audio starts on your first tap on Play, as required by your browser. Press Space to start or stop.

An online tone generator plays a pure test tone at exactly the pitch you ask for. Use this sine wave generator, also called a frequency generator, to send a steady tone between 20 Hz and 20 kHz to your speakers, headphones or a measurement app, glide it across a range, and save the result as a WAV file.

How to use it

  1. Pick a mode. A steady tone holds one frequency until you stop it. A frequency sweep glides from a start frequency to an end frequency over the duration you set, on a linear or a logarithmic curve.
  2. Set the frequency. Drag the slider for a coarse move, type an exact value in hertz, or tap a preset: 100 Hz, 432 Hz, 440 Hz, 1 kHz or 10 kHz. The octave buttons halve and double it, and the arrow keys step in fine increments while the slider has focus.
  3. Choose a waveform. Sine is the clean reference tone. Square, sawtooth and triangle stack harmonics on top of the fundamental, so they sound brighter and much louder: turn the volume down before you switch.
  4. Set the level in decibels and the stereo balance, then press Play or hit the space bar. The oscilloscope shows the waveform that is going out.
  5. To keep a tone, pick a file length of 1, 5, 10 or 30 seconds and press Download WAV. The file is rendered from the current settings, and a sweep is exported over its own duration.

What you can use it for

Speaker and headphone checks. Play one frequency at a time and listen for buzz, rattle or plain silence. If 1 kHz is loud but 60 Hz is missing, the cabinet is the limit rather than the recording, and a slow sweep finds the point where a small driver gives up.

A tuning reference. 440 Hz is concert pitch A4, the note most orchestras and tuners agree on, and the 432 Hz preset covers the alternative tuning some players prefer. Sound the tone, then match your string or your voice to it by ear.

Checking your own hearing range. Start around 8 kHz and work upward. The top of the range is the first part to go with age, so the frequency where the tone disappears says something about your ears, and something about your headphones.

Feeding measurement tools. A steady tone is a known input for a spectrum analyzer, a sound level meter, a recording chain or a video call, so whatever comes out at the far end can be compared against what went in.

Physics you can hear. A low tone carried slowly around a room reveals standing waves where the level drops away, and a sweep finds the frequency at which a shelf, a cabinet or a glass starts to resonate.

Common test frequencies

FrequencyWhat it checks
20 HzThe bottom of the audible range. Laptop and phone speakers put out nothing here, so you feel it on a subwoofer or not at all.
60 HzBass body and cabinet rattle. It is also the mains hum frequency in North America; in Europe the hum sits at 50 Hz.
440 HzConcert pitch A4, the reference for tuning. Every speaker reproduces it, which makes it a safe level check.
1 kHzThe standard reference tone for levels and distortion. If a system passes anything, it passes this.
8 kHzPresence and sibilance. Small drivers and tired tweeters begin to fall away around here.
15 kHzThe top octave. Many adults over 40 no longer hear it, and plenty of speakers no longer send it.

Accuracy and limits

Nothing here is calibrated. The browser cannot know how loud your speakers are, so the same -20 dB setting is inaudible on one machine and painful on the next. Treat the volume slider as relative, and leave it untouched when you compare two runs.

The chain after the browser counts as much as the tone. Equalizers, spatial audio, loudness normalization and Bluetooth codecs all reshape the signal, and small drivers roll off long before 20 Hz and above 15 kHz. When a frequency goes missing, the playback chain is the usual reason. The slider also rounds to whole hertz, so type into the number field when you need a value in between.

Frequently asked questions

What is a tone generator used for?

Testing and tuning. It gives you a signal with one known frequency, which is what you need to find out whether a speaker, a headphone driver, a recording chain or your own hearing still handles that part of the spectrum.

What frequency should I use to test my speakers?

Start at 1 kHz for a level reference, then work down through 100 Hz and 60 Hz to 20 Hz to find where the bass stops, and up through 8 kHz to 15 kHz for the top end. Sweep mode covers the whole range in one pass.

Why can I not hear 17 kHz?

Your equipment, your age, or both. Hearing loses its top octave gradually from the early twenties on, and most laptop and phone speakers produce very little above 15 kHz. Wired headphones give the fairest answer.

Is it safe to listen to test tones?

At a low level, yes. High frequencies are the risk, because they sound quiet even when the level is high, so it is easy to run your ears harder than you mean to. Start quiet, raise slowly, and stop if you feel pressure or pain.

Does the tone generator work offline?

Yes. The page is cached on your first visit and the tone is generated by the Web Audio API on your own device, so you can disconnect the network and it keeps playing.

Can I download a tone as an audio file?

Yes. Pick 1, 5, 10 or 30 seconds and press Download WAV. The file is rendered in your browser with the current waveform, level and balance, and it never touches a server.