Choose a frequency with the slider, a preset, or the exact Hz field, then tap Play tone. The − and + buttons change it by one hertz. Stop sound is available while starting or playing. Each run ends after 60 seconds.
A frequency, at your fingertips
Use a reference tone for music practice, a classroom demonstration, or an informal audio-equipment check. Sine generates a single frequency; triangle, square and sawtooth waves also contain higher-frequency harmonics and sound different. Waveform options are below the main controls.
Keep the level low
Begin with low device volume and tone level. Stop if a sound is uncomfortable. Don’t raise the volume to compensate for a very high or low tone you cannot hear: your speakers may not reproduce it, and the page cannot measure the sound level reaching your ears. See WHO guidance on safe listening.
Why can’t I hear a selected frequency?
Hearing and speaker response both vary. Your output device, Bluetooth routing or browser may limit the range. If the audio system’s sample rate cannot represent a selected frequency, the tool stops and asks you to choose a lower one. A moving interface is not proof that your speakers produced the tone.
Does it keep playing in the background?
No. Leaving the visible page, opening help or an audio interruption stops playback. Returning never restarts it automatically. Tap Play to begin another bounded run.
Can this test hearing or repair speakers?
No. It generates sound, but does not assess hearing, calibrate acoustic loudness, diagnose equipment or repair a speaker. For a simple left/right routing check, use the speaker test.
Does this record or upload anything?
No microphone permission is needed. The browser synthesizes sound locally; selected frequencies and levels are not saved or sent to analytics. General site analytics are described on Privacy.
Also useful: mosquito tone generator · speaker test · metronome.