Tone Generator

A free online tone generator that plays a pure sine, square, sawtooth, or triangle tone from 20 Hz to 20,000 Hz.

Play a pure tone at any frequency from 20 Hz to 20,000 Hz right in your browser. Great for testing speakers and earphones, checking your hearing, or getting a reference pitch. Keep the volume low to protect your ears.

Start with the volume all the way down, then bring it up slowly — high frequencies at loud levels can damage your hearing. Drag the slider or type an exact frequency to fine-tune.

Frequency (Hz)

Frequency440 Hz

Preset

Waveform

Volume30%

Channel

About This Content

A free online tone generator and frequency generator that plays a steady pure tone from 20 Hz to 20,000 Hz right in your browser. Pick a waveform (sine, square, sawtooth, triangle), set the exact frequency with the slider or input, adjust the volume, and send the sound to the left, right, or both channels. Perfect for testing speakers and earphones, checking your hearing range, generating a mosquito tone, or getting a reference pitch for tuning instruments. Everything runs on your device — no install, no sign-up, nothing sent to a server. Start at a low volume, since loud high frequencies can harm your hearing.