How to read your result
The big number is the frequency in hertz (Hz): how many times per second the sound wave repeats. Higher numbers sound higher. The generator covers 20 Hz to 20,000 Hz.
The slider is on a log scale, the way pitch works for the ear. Each third of the slider is ten times higher than the last: 20 Hz, 200 Hz, 2,000 Hz and 20,000 Hz. To set an exact value, type it in the number box.
| Control | What it does |
|---|---|
| Arrow keys on the slider | Move 1 Hz up or down |
| Page Up and Page Down | Move one semitone (one piano key) |
| Home and End | Jump to 20 Hz or 20,000 Hz |
| Octave down and Octave up | Halve or double the frequency |
Nearest note shows the piano note closest to the frequency, worked out with A4 = 440 Hz. A cent is one hundredth of a semitone, so “+21 cents” means a little above the note.
| Frequency | Nearest note |
|---|---|
| 261.63 Hz | C4 (middle C), exactly |
| 440 Hz | A4, the usual tuning note, exactly |
| 100 Hz | G2, +35 cents |
| 1,000 Hz | B5, +21 cents |
Waveforms change the colour of the sound, not its pitch:
- Sine: a pure, smooth tone with a single frequency. Use it for most checks.
- Square: hollow and buzzy.
- Sawtooth: bright and harsh.
- Triangle: soft, between sine and square.
Square and sawtooth waves are played quieter than sine so the four sound about equally loud.
Volume always starts at 25%. Above 70% the panel shows a reminder to turn down before changing the frequency. Every start and stop fades in and out over a moment, so there is no click.
Balance moves the tone between the left and right speaker. Use it to check each side on its own.
The page address keeps your settings after the # sign, for example #f=440&w=sine. Volume is never saved in the link, so a shared link always starts quiet.
Start quiet and raise the volume slowly, especially with headphones. Very high and very low tones can seem silent until they are loud, and loud tones can damage speakers. This is a sound source for checking equipment and tuning. It is not a medical tool.
Troubleshooting
I can’t hear anything
- Try 440 Hz with a sine wave first. If you hear that, sound is working.
- Check the volume, the mute key and which output device is selected in your system sound settings.
- Small laptop and phone speakers often can’t play deep bass tones, and the highest tones are hard to hear for many listeners. Neither means something is broken.
- iPhone and iPad: turn off Silent mode and raise the volume with the side buttons.
The tone crackles or sounds distorted
Lower the volume, then switch to a sine wave. Square and sawtooth waves are rich in high overtones that small speakers struggle with. Bluetooth headphones can also crackle when the connection is weak: move closer to the device.
The tone only plays in one ear
Check that Balance shows Center. If it does, your system may have mono audio or an uneven balance turned on.
- Windows: Settings, then Accessibility, then Audio. Turn off Mono audio.
- Mac: System Settings, then Accessibility, then Audio. Turn off Play stereo audio as mono. Balance is under System Settings, then Sound, then Output.
- iPhone and iPad: Settings, then Accessibility, then Audio and Visual. Turn off Mono Audio and center Balance.
- Android: Settings, then Accessibility, then Audio adjustment or Hearing enhancements. Turn off Mono audio and center the balance.
The speaker test checks left and right in a few seconds.
How do I share or save a tone?
Press Copy link and paste it anywhere, or bookmark the page. The link keeps the frequency, waveform and balance.
Does it keep playing in another tab?
Yes. The tone plays until you press Stop tone or the Esc key, or close the page. Phones may pause it when the screen locks.
Privacy
The tone is made by your browser’s built-in audio engine, so no sound files are downloaded and no microphone is used. Your settings live only in the page address after the # sign, which browsers do not send to websites. How it works