Tone Generator

How to use

1. Lower the device's system volume before starting, especially when using headphones. The page cannot control OS volume, amplifier gain, an external DAC, powered-speaker gain, or headphone sensitivity.
2. Choose a frequency from 20 Hz to 20 kHz with the slider, number field, or a 100 Hz, 250 Hz, 440 Hz, 1 kHz, 4 kHz, or 8 kHz preset.
3. Choose Sine, Square, Triangle, or Sawtooth. Sine is the simplest reference; Square and Sawtooth contain stronger harmonics and may sound harsher or louder.
4. Choose Left, Center, or Right pan. This requests a browser stereo position; mono output, OS balance, the connected device, and browser support can change what you hear.
5. Keep App output gain low. It limits the page's internal Web Audio gain from 0.02 to 0.35, but it is not system volume, a calibrated dB SPL reading, or an acoustic safety guarantee.
6. Click Start continuous tone. Browsers require a direct user interaction and may suspend Web Audio until you click.
7. While the continuous tone is playing, you can change its frequency, waveform, or pan and the page updates the active oscillator.
8. Click Stop all sounds as soon as you finish or if you notice discomfort, tinnitus, pain, dizziness, or any unusual sensation.
9. For a frequency sweep, enter the start frequency, end frequency, and duration in milliseconds. Both frequencies are limited to 20–20,000 Hz and duration to 200–30,000 ms.
10. Click Start frequency sweep. It replaces any current sound, uses a sine waveform, moves exponentially between the endpoints, and stops automatically at the selected duration.
11. Switching tabs or hiding the page stops every sound. Return to the page and click Start again if you want to resume.
12. Do not raise the volume to search for an inaudible frequency or use this page to determine a hearing threshold. It needs no camera or microphone permission and does not analyze what you hear.

What the result means

• Requested tone frequency is the fundamental frequency requested from the Web Audio oscillator during continuous playback. A sweep instead reports its requested start and end range; neither is a microphone measurement or proof of the frequency produced acoustically by your speaker or headphones.
• Sine is dominated by one fundamental frequency and is usually the clearest general reference, but it is still not calibrated. Square contains strong odd harmonics; Triangle also contains harmonics but is usually gentler; Sawtooth contains a rich harmonic series and can sound brighter, rougher, or louder.
• Left, Center, and Right are browser pan requests. Their audible position depends on stereo output, browser support, OS balance, connected headphones or speakers, and whether the path has been mixed to mono. Pan is not a physical channel diagnosis.
• Audio status reports the Web Audio context state: Ready before use, Playing while the page has an active source, Browser suspended — click Start/Resume when browser policy pauses the context, Stopped — audio is closed after the context closes, or Not supported when Web Audio is unavailable.
• Playing Yes means the page currently owns an active source; No means it does not. This page state does not prove that you can hear the tone or that a speaker produced acoustic output.
• A frequency sweep changes a sine oscillator from the requested start frequency to the requested end frequency over the selected duration and stops automatically. It records no audible threshold and is not an audiogram or frequency-response measurement.
• Frequency is the oscillator's cycles per second in hertz (Hz). Pitch is the subjective perception of how high or low a sound seems: it relates to frequency but is not identical. This page generates output; Pitch Detector estimates pitch from microphone input.
• Loudness is a perception affected by system volume, device frequency response, waveform, headphones or speakers, environment, and individual hearing. The page's output slider is not dB SPL, and equal slider values can sound very different across frequencies and waveforms.
• The 20 Hz–20 kHz values are the page's allowed digital settings, not a promise that every device reproduces—or every person hears—the full range. Small speakers may rattle, distort, or produce almost no low-frequency output; high-frequency output may fall rapidly or be altered by device processing.
• Not hearing a frequency can reflect the output device, system processing, browser, environment, level, or personal hearing. Do not infer hearing loss or keep increasing the level; this page cannot measure a hearing threshold.

Limitations

• The page limits only its internal Web Audio gain. It does not control system volume, amplifier gain, an external DAC, powered speakers, headphone sensitivity, or the resulting sound pressure level.
• It is not calibrated in dB SPL and cannot measure acoustic output, speaker distortion, room response, device frequency response, or whether the requested digital frequency reached the air accurately.
• It is not a medical hearing test, tinnitus test, audiogram, or diagnostic tool. Do not use an inaudible frequency as evidence of hearing loss.
• Long pure tones can cause listening fatigue. High frequencies and non-sine waveforms may be especially harsh; stop immediately for discomfort, tinnitus, pain, dizziness, or an unusual sensation.
• Square, Triangle, and Sawtooth include harmonics beyond the displayed fundamental frequency. For a simpler frequency reference, use Sine and keep the output level low.
• Low frequencies may be inaudible or distort on phones and small speakers. Rattling is not proof that the requested oscillator frequency is wrong, and it is not a reason to raise the level.
• Sweeps are clamped to 20–20,000 Hz and 200–30,000 ms, use a sine waveform, and stop automatically. They do not measure hearing thresholds, speaker calibration, room response, or frequency response.

Troubleshooting

No sound after Start

Confirm the tab and system are not muted and the correct OS output device is selected. Lower volume first, try 440 Hz Sine, and click Start again because browsers require user interaction. No microphone or camera permission is required; try another supported browser if needed.

Audio status says Browser suspended

Click Start continuous tone directly. Browser autoplay policy may suspend Web Audio until a user interaction; do not request media permissions.

The tone stops after switching tabs

This is expected safety behavior: hiding the page stops all sound. Return to the tab and click Start again.

Low frequencies are silent or distorted

Small speakers may not reproduce them. Reduce the output level and, only if appropriate, try capable headphones or speakers cautiously; do not increase volume aggressively.

High frequencies are silent

Output-device response, system processing, the environment, or hearing may be involved. Do not force audibility by raising volume and do not treat this as a hearing diagnosis.

Square or Sawtooth sounds much louder or harsher

These waveforms contain stronger harmonics. Lower the output level or switch to Sine for a simpler frequency reference.

Left or Right pan is unavailable or does not sound directional

The page disables Left and Right when the browser does not expose StereoPanner. When available, mono output, OS balance, accessibility settings, and the connected device can still alter the audible position. Use Stereo Test for a dedicated channel workflow.

The sweep stops before expected

Check the duration field. Switching tabs stops audio, starting another sound replaces the current source, and values outside the allowed ranges are sanitized.

A speaker rattles

Stop immediately, lower the level, and avoid extreme low frequencies. Rattling does not prove the page generated an incorrect digital frequency.

Bluetooth output is delayed or changes quality

Bluetooth codecs and device processing can add latency or filtering. Tone generation does not measure Bluetooth latency or frequency response.

Stop all sounds does not appear immediate

The tool uses a very short fade to reduce clicks, then stops the audio. This deliberate fade is not a continuing test session.

Related tools

• Speaker Test

  Run a left/right speaker test with finite tones, center, frequency checks, and a sweep. Record what you hear locally; the browser cannot listen or certify speaker health.

• Headphone Test

  Check headphone and earbud left/right routing, center, bass, high tone, and phase with finite browser-generated signals you confirm yourself.

• Stereo Test

  Check left/right routing, center image, a finite left-to-right pan sweep, and bounded phase references with locally generated audio you confirm yourself.

• Pitch Detector

  Estimate a dominant pitch from local microphone input and view frequency, note, octave, cents, confidence, and adjustable A4 tuning—not laboratory calibration.

FAQ