A tone generator produces a pure audio frequency at any pitch you choose. Use it for hearing range tests, instrument tuning reference, audio equipment testing, tinnitus masking research, or music production.
How to Use the Online Tone Generator
This free online tone generator creates precise audio frequencies using your browser's Web Audio API. Type a frequency or use the slider, choose a waveform, set volume, and click Play. The tone plays continuously until you click Stop.
Setting a Specific Frequency
Type directly into the frequency field for precise values (e.g., 432 for A4 Natural Tuning) or drag the slider for quick exploration. The slider covers 20 Hz to 20,000 Hz — the full range of human hearing. Frequencies below 50 Hz are felt as much as heard; above 15,000 Hz is the high-treble/air range.
Common Uses for a Tone Generator
Speaker and headphone testing: Play a sweep from 20 Hz to 20 kHz to identify resonances or distortion at specific frequencies. A 100 Hz tone tests bass response; 10 kHz tests treble extension.
Hearing range check: Start at 20 kHz and sweep down. The frequency at which you first hear the tone is your upper hearing limit. Younger people can often hear up to 18–20 kHz; this typically decreases with age.
Instrument tuning: The 440 Hz A4 preset is the international concert pitch standard. Play it and tune your instrument's A string to match.
Tinnitus frequency matching: If you have ringing in your ears, use the generator to find the closest matching frequency for logging purposes (not a medical tool).
Choosing a Waveform
For pure tone tests and tuning reference, use Sine — it has no harmonics and produces the cleanest, most neutral sound. For musical or synthesizer-style tones, Square and Sawtooth add harmonic richness. Triangle is between sine and square — gentle with mild harmonics.
FAQ
What frequencies can this tone generator produce?
The generator covers the full human hearing range from 20 Hz (very low bass) to 20,000 Hz (20 kHz, the upper limit of typical human hearing). Most adults can hear up to about 16–18 kHz, so frequencies above that are useful for testing high-frequency hearing.
What is the difference between sine, square, sawtooth, and triangle waves?
Sine waves are pure tones with no harmonics — smooth and neutral. Square waves have a hollow, buzzing quality with odd harmonics. Sawtooth waves are bright and cutting, containing all harmonics (used in synthesizers). Triangle waves are softer than sawtooth with weaker harmonics — similar to a flute.
What is A440 (440 Hz)?
A440 is the international standard concert pitch — the A above middle C. Musical instruments worldwide are tuned so that this note vibrates at exactly 440 Hz. Orchestras and bands use this as their reference pitch for tuning.
Is this tool free?
Yes, completely free with no account or download needed. It runs entirely in your browser using the Web Audio API.
Is my audio data private?
Yes. All audio is generated locally. No sound data leaves your browser.
Can I use this for a hearing test?
You can use it to test which frequencies you can hear, but this is not a medical hearing test. For a proper audiogram, see a licensed audiologist.