Tone Generator

Play a pure tone at any frequency, free and in your browser. Choose the waveform, read the note name, and tune by ear. The tone is synthesised on your device — nothing is uploaded.

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A4in tune

The note name is the nearest equal-tempered pitch with A4 fixed at 440 Hz; the cents readout shows how far the exact frequency sits from it. Use a sine wave for a clean reference tone, or square / sawtooth / triangle for a richer, harmonic-heavy sound. High volumes and high frequencies can be harsh on speakers and ears — start low. The tone is synthesised in your browser.

How to generate a tone

Enter a frequency in hertz (or drag the fine-tune slider), choose a waveform, then press Play tone. The readout names the nearest note with A4 fixed at 440 Hz and shows how many cents sharp or flat your frequency is.

Using it to tune an instrument

Set the frequency to the note you want — for example 440 Hz for concert A — pick a sine wave, and match your instrument to the steady reference pitch by ear. The cents readout helps you confirm an exact frequency lands on the note you intend.

Questions

What frequency range can it generate?
From 20 Hz to 20,000 Hz — the full range of typical human hearing. Type an exact frequency or drag the slider for fine control, and the nearest musical note name and cents-off reading update live.
Which waveform should I use?
A sine wave is a pure single-frequency tone, ideal as a tuning or test reference. Square, sawtooth, and triangle waves add harmonics for a brighter, buzzier sound — useful for ear training or testing how a speaker handles richer signals.
Is it safe for my speakers and ears?
Keep the volume moderate. Sustained high-frequency or loud tones can be uncomfortable and, over time, hard on hearing and on small speakers. Start quiet and raise it only as needed. The tone is generated on your device and nothing is uploaded.