Free hardware tester
Tone Generator: 20 Hz to 20 kHz Online
Runs locally in your browser. Nothing is uploaded.
Web Audio tone controls
Generate a local tone, select its waveform and channel, and stop it instantly.
This is an uncalibrated output and routing tool, not a hearing test. Browser, device, amplifier, speaker, and room response all affect what reaches you.
Last updated: July 29, 2026
Tone generator: This online tone generator uses the Web Audio API to create a steady local signal from 20 Hz to 20 kHz with four waveforms, bounded volume, and stereo channel selection.
How this tone generator works
Start with device volume low. Enter a frequency or use the slider, choose sine, square, triangle, or sawtooth, select a channel, and start the tone. Stop sound before disconnecting an output or switching devices.
How to read the results
A stable tone confirms that the browser can route generated audio to the selected output. It does not measure speaker frequency response or listening ability. Harmonics make square, triangle, and sawtooth waves sound brighter than a sine wave at the same fundamental frequency.
Common causes of failed tests
No output can result from a muted browser, wrong operating-system output, Bluetooth profile change, disconnected cable, disabled Web Audio, or an amplifier in protection mode. Missing low or high tones may reflect the playback chain and room, not only the speaker.
Troubleshooting before you replace hardware
Lower volume, confirm the active output and application mixer, play a moderate 440 Hz sine tone, and compare headphones or another browser. Do not raise volume to force an inaudible or unsupported frequency.
For setup and buying context, see the tone generator, left/right speaker test, audio channel test, bass test, subwoofer test, and DTMF tone generator.
Frequently asked questions
What waveforms can this generate?
It supports sine, square, triangle, and sawtooth oscillators.
Is this a hearing test?
No. It is an uncalibrated audio-output generator and makes no hearing assessment.
Does audio leave the browser?
No. The sound is generated locally with the Web Audio API.