Tone Generator

How to use the tone generator

Type a frequency, drag the slider, or use the arrow keys, then press Play. The tone keeps playing until you press Stop, and you can change the frequency while it plays without any clicks or pops. Start with the volume low and raise it gradually.

For fine control, use −1 and +1 to move by one hertz, or −10 and +10 for bigger steps. ÷2 and ×2 jump down or up by exactly one octave, which is handy for music and for checking how a speaker handles the same note in different ranges. On a keyboard, the up and down arrows change the frequency by 1 Hz, or by 10 Hz with Shift held.

You can also choose a waveform, send the tone to Left, Right or Both channels, and pick from presets such as 440 Hz or 1 kHz. The page remembers your last settings. To share an exact tone with someone, press Copy link — the link opens this page with the same frequency and waveform ready to play.

Sending a tone to one channel at a time is a quick way to compare two speakers or two earbuds. Play the same frequency on Left, then on Right, and listen for differences in loudness or clarity.

Common test frequencies

• 50–100 Hz: checking bass and subwoofers.
• 440 Hz: the A above middle C, the standard reference pitch for tuning.
• 1,000 Hz: a common reference tone for checking audio levels.
• 10,000–15,000 Hz: checking tweeters and high-frequency output.

This hz tone generator isn't limited to these values. Any frequency from 1 to 20,000 Hz is available, with one decimal place if you need it. Very low settings, below about 20 Hz, are mostly useful for experiments, since most speakers and headphones can't reproduce them as audible sound.

A simple routine for checking a speaker is to step through a handful of frequencies at the same volume — for example 100 Hz, 500 Hz, 1 kHz, 5 kHz and 10 kHz. Each should sound clean. A buzz, rattle or crackle at one of them points to a loose part, a damaged driver, or something nearby vibrating along.

Sine, square, triangle and sawtooth

A sine wave is a pure tone with a single frequency — the best choice for testing speakers and headphones. Square and sawtooth waves contain many higher harmonics, so they sound buzzy and seem much louder at the same volume setting. Triangle is in between: softer than a square wave, but not quite as pure as a sine.

The page automatically lowers the level of square and sawtooth waves to protect your ears and speakers, but it's still a good idea to turn down before switching waveforms. If you're unsure which to use, choose sine.

The other waveforms still have their uses. Square and sawtooth waves are the building blocks of many synthesizer sounds, so they're useful for music lessons and for hearing how harmonics change the character of a note.

Frequency test: speakers and hearing range

A slow sweep is the easiest way to run a frequency test. Open the Sweep panel, set a start and end frequency and a duration, and listen to where your speakers or headphones start and stop producing sound. A smooth sweep should rise steadily without sudden jumps in loudness, rattles or dropouts.

Longer sweeps are easier to follow. A sweep of 20 or 30 seconds gives you time to notice where the sound fades, and you can stop at any point and note the frequency on screen. Sweeping in both directions, low to high and then high to low, helps confirm what you heard.

Results depend on your device, your volume, your room and your age, so two people can get different answers with the same setup. This is not a hearing test. If you're worried about your hearing, see a hearing professional.

High frequency test and age

The upper limit of human hearing is often quoted as about 20,000 Hz, and it's normal for the highest frequencies we can hear to drop with age. It's also common for a speaker or pair of earbuds to roll off before that limit, so silence at the top of the range doesn't tell you which one is the cause.

Keep the volume low for any high frequency test. Very high tones can be unpleasant even when they seem quiet, and you may not notice how loud they are until you stop. Short checks are enough.

Common uses

People use a frequency generator like this one for tuning instruments, checking speaker and headphone response, finding rattles in a room, science lessons and simple audio experiments. Teachers often use it to show how pitch changes with frequency, and musicians use 440 Hz as a quick tuning reference.

Every tone is generated live in your browser with the Web Audio API, so there's nothing to download and nothing is uploaded. That also means it works the same way on a phone, a tablet or a computer, as long as the browser is reasonably up to date.

If you're thinking about using tones for tinnitus or any other health reason, talk to a doctor first. This tool is for testing and learning, and it doesn't treat any condition.

Related tests

For deep bass and subwoofers, use the Bass Test. To check that each speaker is on the correct side, use the Left Right Speaker Test.