Tone & Frequency Generator
Play any frequency from 20 Hz to 20 kHz as a sine, square, sawtooth or triangle wave, and download it as WAV.
Stopped. Press Play tone to start.
Start at a low volume. Loud tones — especially high frequencies and square waves — can damage hearing and speakers.
How it works
Type a frequency (or drag the logarithmic slider) and press Play tone: your browser's Web Audio API creates an oscillator at exactly that pitch and sends it straight to your sound card. Everything updates while the tone is playing, so you can sweep the frequency, switch between sine, square, sawtooth and triangle waves, or route the sound to only the left or only the right channel to check which speaker is which. The readout shows the nearest musical note with its cents offset — handy for tuning an instrument by ear — plus the wavelength of the tone in air at room temperature.
Common uses: testing speakers, headphones and subwoofers, a rough hearing check (most adults stop hearing somewhere between 15 kHz and 17 kHz), tuning to A4 = 440 Hz, finding room resonances, and generating reference tones for audio gear. Download WAV writes the tone to a 44.1 kHz 16-bit stereo WAV file entirely in your browser, with a short fade in and out so it starts and stops without a click. No audio is uploaded and no account is needed — the tool is a single static page with no ads and no tracking.
Frequently asked questions
How do I generate a 440 Hz tone online?
Type 440 in the frequency box (or press the 440 Hz (A4) preset), leave the waveform on sine and press Play tone. Your browser's Web Audio API generates the pitch live, so you can change frequency, waveform or volume while it is still playing. A4 = 440 Hz is the standard concert pitch used to tune instruments.
Can I use a tone generator to test my speakers or headphones?
Yes. Set the channels dropdown to Left only or Right only to check that each speaker is wired and working, then sweep the frequency slider from 20 Hz upwards to hear where your speakers or subwoofer start and stop reproducing sound. Start quietly: loud low-frequency tones and square waves can damage drivers.
What frequency range can humans hear?
Healthy young ears hear roughly 20 Hz to 20,000 Hz. High-frequency hearing drops with age, so most adults stop hearing somewhere between 15 kHz and 17 kHz. Use the 15 kHz preset for a rough check, but this is a fun test, not a medical audiogram, because the result depends heavily on your speakers and volume.