Generate a tone
Choose a frequency from 20 to 20,000 Hz, one of four oscillator waveforms and a playback length. Five seconds is the safe default.
Enter an exact whole number or use the logarithmic slider for faster changes across the range.
Nearest equal-tempered note (A4 = 440 Hz): A4 · 0 cents
Ready at 440 hertz, sine wave
Lower the device volume first. Non-sine waves contain added harmonics and may sound sharper. Keep headphones off your ears for the first tone and stop for discomfort, pain or ringing. Continuous mode stops when you press Stop, leave the page or hide the tab.
Quick answer: lower the device volume, enter a frequency or choose a preset, select a waveform (sine is the default), then play it or download a 5- or 30-second WAV. Playback and export run locally in your browser; no audio is uploaded and no microphone is required. Start with the output away from your ears. This browser tool generates a reference signal; it does not measure loudness, frequency response, hearing or hardware condition.
The note label is a mathematical comparison with the nearest equal-tempered pitch using A4 = 440 Hz as its reference. It does not tune an instrument or measure the sound from your output device; the displayed cents difference describes only the requested frequency.
Download a custom tone as WAV
Choose a 5- or 30-second file length and download a mono, 16-bit PCM WAV rendered at 44.1 kHz from the selected frequency and waveform. The file is generated in this browser and is not uploaded. Its sample format does not calibrate the sound coming from your speaker or headphones.
Looking for the common 165 Hz water-eject reference? Choose the 165 Hz preset for a short inspectable tone, then read why 165 Hz is not a proven universal optimum. The water eject sound player on the SpeakerEject homepage uses a separate 165–230 Hz sweep.
What the frequency generator does
The control asks the browser's Web Audio API to create an oscillator at the selected frequency and waveform. It accepts whole numbers from 20 to 20,000 Hz and can stop after five or 30 seconds, or continue until you press Stop, leave the page or hide the tab. The logarithmic slider gives more control over lower frequencies than a linear slider across the same range.
The requested frequency is a software setting, not proof that the connected device reproduced that frequency accurately or audibly. Speakers, headphones, amplifiers, operating-system processing, room acoustics and individual hearing all affect the result.
How to use an online tone generator
- Turn the system or amplifier volume down before starting.
- Confirm the selected output device. Disconnect any Bluetooth output you do not intend to test.
- Keep headphones off your ears for the first tone.
- Enter an exact frequency, move the slider or choose a preset. Leave the waveform on sine for a simple reference, or choose another waveform to compare harmonic character.
- Use the half and double buttons to move one octave while staying within 20–20,000 Hz. Keep the five-second default for a quick check; use 30 seconds or continuous mode only when the task requires a sustained reference.
- Stop for discomfort, pain, ringing, heavy distortion or mechanical knocking.
Why is the tone generator not making sound?
Keep this tab visible and press Play; a shared setting link never starts sound automatically. Check whether the tab is muted and whether your device is sending audio to the intended speaker or headphones. Browser playback permissions can also prevent Web Audio from starting; see MDN's browser playback guide.
At a low volume, try the 1 kHz sine preset for five seconds rather than turning up a very low or high tone you cannot hear. If playback still fails, download a five-second WAV and open it in another audio player. A difference between players can help narrow the playback path, but neither result diagnoses your hearing or proves a hardware fault. For a separate left/right comparison, use the speaker test.
Choose a waveform
Sine
The simplest reference: one oscillator frequency without the added harmonics built into the other waveform shapes.
Triangle
A softer harmonic waveform. It sounds brighter than a sine wave but usually less sharp than square or sawtooth.
Square
A strong odd-harmonic waveform with a sharper character. The tool lowers its output gain, but you should still start quietly.
Sawtooth
A dense harmonic waveform that can sound especially bright. Keep the listening level low and the test short.
The setting link stores only the selected frequency and waveform in the URL. It deliberately returns to the five-second default, and opening it prepares the controls but never starts audio automatically.
Useful reference frequencies
60–100 Hz
Low-frequency references for bass-capable speakers and subwoofers. Small speakers may reproduce little or none of the requested tone.
250 Hz–1 kHz
Midrange references that many speakers reproduce more readily. Use the dedicated speaker test when you also need left/right routing.
4–8 kHz
Higher-frequency references. Begin especially low and never raise the volume simply because a tone seems quiet.
Above 8 kHz
Audibility varies with age, hearing, equipment and processing. An absent tone does not identify which factor is responsible.
How long can the tone play?
Five seconds is the default for a quick reference. Thirty seconds supports a longer comparison. Continuous mode keeps the oscillator active only while this page remains visible and stops when you press Stop, leave the page or hide the tab. The frequency, waveform and duration controls are locked while audio is active so the visible settings always describe the sound being generated.
Keep playback controlled
The World Health Organization advises limiting loud-sound exposure and keeping personal-device volume below 60% of maximum. That percentage is only a precaution here because SpeakerEject cannot know the acoustic level produced by your device, amplifier and output. Start lower and keep tests brief.
Sources and technical references
For continuous movement between two chosen frequencies, use the frequency sweep generator. For a guided 20–120 Hz comparison, use the bass and subwoofer test. For channel routing and fixed reference tones, use the speaker and sound test; for a dedicated left/right headset check, use the headphone test; for more than two channels, use the surround sound test. To hear phone keypad tones, use the DTMF tone generator.