What is a tone generator?
A tone generator plays one clean sound at the pitch you choose. You type a number in hertz (Hz) and the tool plays that exact tone. It all happens inside your browser, so the sound starts the moment you press play. Nothing to download, nothing to set up.
You can play a low 40 Hz tone that you feel more than hear, a middle tone like 440 Hz, or a 15,000 Hz tone near the top of human hearing. Some people call this an hz generator; others call it a frequency generator. Same thing.
Why people use one
Any pitch
Play anything from 1 Hz to 20,000 Hz. Type a number, or step it one hertz at a time.
Four sound shapes
Sine is the cleanest tone. Square, sawtooth and triangle sound fuller and sharper.
Left and right
Send the sound to one side or keep it centred, so you can test each speaker on its own.
Changes right away
Move a slider and the sound follows while it plays. No stopping and starting.
Easy to share
Copy a link that remembers your tone. Anyone who opens it hears the same thing.
Works on any device
Phone, tablet or computer — the tool behaves the same on all of them.
Ways to use it
- Test speakers and headphones. Sweep through a few tones to find buzzing, rattles, or a side that plays quieter than the other.
- Check your hearing. Raise the pitch slowly and notice where the tone disappears for you.
- Tune an instrument. Hold a steady note and match your instrument to it by ear.
- Ease ringing ears. Play a soft tone close to the ringing you hear. Keep the volume low.
- Teach how sound works. Show pitch, waves and frequency with no extra equipment in the room.
- Set up audio gear. Feed a known tone into a mixer or amp to set levels before a show.
How do you pick the right frequency?
Start with what you're trying to hear. Around 20 to 60 Hz is where subwoofers live, so that range shows up rattles in a car door or a loose speaker grille. The middle of the range, roughly 200 Hz to 2 kHz, is where voices sit, and it's the easiest place to judge whether two speakers are matched. Above 10 kHz you're testing tweeters and your own ears at the same time.
For tuning, 440 Hz is the standard A that most orchestras and apps use. Use the sine shape for anything you want to match by ear — the other shapes add extra tones on top and make pitch harder to judge.
What the sound shapes actually do
A sine wave is a single frequency and nothing else. It sounds smooth, almost hollow, and it's the right choice for testing and tuning.
Square, sawtooth and triangle waves stack extra frequencies on top of the one you picked. That's why they sound brighter or buzzier at the same number of hertz. Square waves are handy for hearing whether a speaker distorts; sawtooth is closer to a synth or a string sound; triangle sits in between and is gentler on the ears than square.