Tone Generator
Play reference tones at any frequency with sine, square, sawtooth, and triangle waves.
Requires Web Audio API
How to Test
- •Choose a frequency and waveform, then press Play.
- •Adjust volume gradually — start low to protect your ears and speakers.
- •Use the preset frequencies to check channel response across the audible range.
Browser Limitations
- •Sustained high volumes can damage hearing and speakers; keep levels moderate.
- •Output frequency response depends on your playback hardware, not the generator.
Troubleshooting Tips
- •No sound? Check that the correct output device is selected and volume is up.
- •Bluetooth devices may filter very low or very high frequencies.
About the Tone Generator
The Tone Generator synthesises a steady tone at any frequency you choose and sends it straight to your speakers or headphones. It is the fastest way to hear a specific part of the audible spectrum — the low rumble that reveals a loose floor, the top end that reveals dull drivers — without any music, video, or software to install.
You pick a frequency from 20 Hz to 12,000 Hz, choose a waveform — sine, triangle, square or sawtooth — set the output gain, and press play. The tone is generated by an oscillator in the Web Audio graph and stops the moment you press stop, so it is a deliberate output-only tool: it plays sound and measures nothing.
Tips for a reliable result
- Start with the gain low and raise it gradually. Sustained high volume through a tone is the fastest way to fatigue your ears or overdrive small speakers.
- Use the preset frequencies to sweep the range in order — 60 Hz, 120 Hz, 261.63 Hz, 440 Hz, 1,000 Hz and 4,000 Hz — and note where the response drops away.
- Sine is the cleanest reference tone. The square and sawtooth waves add harmonics that are useful for spotting intermodulation but are harsher on sustained listening.
- Expect small speakers to lose the extremes: below roughly 60 Hz and above roughly 12 kHz a laptop or monitor simply has no output there. That is a limit of the hardware, not a fault.
- Do not use this while recording from the same machine — a speaker tone loops straight back into the microphone and will be captured as a loud, distorted loop.
Common problems and fixes
No sound is produced
Check the output device selected in your system sound settings and that the volume is up, then reload the page — the Web Audio context is created fresh on each play.
The tone is audible but thin or distorted
Lower the output gain before adjusting anything else; distortion at high gain is normal. If it persists at a moderate level, test on a different output device to separate the tone from the hardware.
Very low or very high frequencies seem missing
That is usually the reproduction limit of small speakers and cheap Bluetooth codecs, which roll off the extremes aggressively. Confirm the tone is really being generated by trying a mid-range frequency such as 1,000 Hz.
The tone cuts out when the tab loses focus
Browsers are allowed to silence an audio context that is running while its page is backgrounded. Keep the tab in the foreground and press play again if it stops responding.
Tone Generator FAQ
What is the difference between the waveforms?
Sine is a single pure frequency and the cleanest reference. Triangle is a pure tone with gentler harmonics. Square and sawtooth contain strong harmonics, so they sound brighter and harsher but reveal more about how a driver handles a rich signal.
Can this measure my speakers?
No. It generates and plays a tone; it records nothing and calculates nothing. Use it to hear a frequency, then use the Speaker & Headphone Test to check channel separation, or the Microphone Test for input.
Why is the maximum frequency 12,000 Hz?
It is the top of the range most audio hardware and codecs reproduce meaningfully. Frequencies above it are inaudible on ordinary speakers, so generating them would not tell you anything useful.
Is any audio recorded or uploaded?
Never. The oscillator runs entirely in your browser and is disconnected as soon as you stop the tone. Nothing is captured, stored, or sent anywhere.
Related Tools
Speaker & Headphone Test
Verify stereo separation by playing a 440 Hz tone to the left, right, and centre channels, then confirming what you hear.
Online Voice Recorder
Record audio locally with pause/resume, playback, and download — nothing uploaded.
Microphone Test
Live input level meter with pitch detection and voice recorder tabs.