7 sound types
Sine, square, sawtooth and triangle waves, plus white, pink and brown noise for speaker, room and sleep use.
Free · 1 Hz to 20,000 Hz · Works in any browser
Play a pure tone at any frequency from 1 to 20,000 Hz. Choose sine, square, sawtooth or triangle waves, or white, pink and brown noise. Sweep between frequencies, pan left and right, and watch the waveform live.
Note A4, in tune
Quick presets
Sound type
Frequency sweep
Auto stop
Start at a low volume and turn it up slowly. Very high or very low frequencies can be loud before you hear them and may damage speakers or hearing.
Most tone generators play one sine wave. This one gives you every common test signal, precise control and a live view of the sound.
Sine, square, sawtooth and triangle waves, plus white, pink and brown noise for speaker, room and sleep use.
Glide from any frequency to another over a set time, on a log or linear scale, to find rattles and room resonances.
See the nearest note and how many cents sharp or flat you are, which is handy for tuning instruments.
Pan the sound to one ear or speaker to check stereo wiring or match a tone to one side.
An oscilloscope shows the exact shape of the signal, so you can see how each waveform differs.
Type an exact frequency to 0.1 Hz, fade tones in and out without clicks, and set an auto-stop timer.
Play any tone in a few seconds.
Drag the slider, type a number, use the step buttons or pick a preset such as 440 Hz or 1 kHz.
Pick a waveform, or a noise colour for a steady background sound.
Keep the volume low, press Play, then raise it slowly to a comfortable level.
Run a sweep to test your speakers, or move the balance to check the left and right channels.
People hear roughly 20 Hz to 20,000 Hz. The top of that range usually drops with age.
| Frequency | What it is | Typical use |
|---|---|---|
| 20 to 60 Hz | Deep bass | Subwoofer tests and finding room rattles |
| 50 / 60 Hz | Mains hum | Matching electrical hum in audio setups |
| 440 Hz | Note A4 | Standard tuning pitch for instruments |
| 1,000 Hz | Reference tone | Audio level checks and test signals |
| 8,000 to 15,000 Hz | Upper treble | Tweeter tests and checking high-frequency hearing |
| 17,000 Hz and above | Very high pitch | Often heard by younger people but not older adults |
White noise has equal energy at every frequency and sounds hissy. Pink noise is softer and balanced to the ear, so it is used for speaker tuning. Brown noise is deeper and rumbly, and many people find it relaxing for focus or sleep.
Type the frequency in hertz into the big number field, or drag the slider, then press Play. You can fine-tune it in steps as small as 0.1 Hz.
Young people can often hear up to about 17,000 to 20,000 Hz. The top limit usually falls with age. Play the 15 kHz and 17.4 kHz presets at a low volume to compare.
Use a sine wave from 20 to 200 Hz for a subwoofer, or run a log sweep from 20 Hz to 20 kHz for full-range speakers. Listen for rattles, buzzing or sudden drops in volume.
440 Hz is the note A above middle C, known as A4. It is the standard pitch used to tune most instruments.
A sine wave is a pure tone with a single frequency. A square wave adds odd harmonics, which makes it sound buzzier and brighter, like an old video game.
Some people use tones to describe the pitch of their tinnitus, and a sweep can show roughly where your hearing stops. This is not a medical test, so please see a doctor or audiologist for advice.
Small speakers, earbuds and laptops often cannot reproduce very low bass or very high treble. Headphones or a subwoofer will play a wider range.
Yes. It works in modern mobile browsers. On iPhone, make sure the silent switch is off so you can hear the sound.
Pick a frequency, choose a wave or noise, and press Play. Free, precise and works in any browser.
Open the tone generator