Tone Generator
← All toolsA steady drone oscillator you can set by frequency in Hz or by note name — useful for tuning by ear against a reference pitch, checking an interval, or just warming up. The scope beneath it draws the actual waveform coming out of the oscillator in real time, not a canned animation.
Tone Generator
Idle
440.0Hz
A steady drone — start at a low volume, especially with headphones.
How to use the Tone Generator
- Pick a waveform — sine for a pure reference tone, or square/triangle/sawtooth for a brighter, more cutting drone.
- Set the frequency directly in Hz, drag the slider, or choose a note name from the dropdown (equal temperament, A4 = 440 Hz).
- Tap Play — the oscilloscope starts tracing the live waveform. Adjust frequency, waveform or volume freely while it plays; changes are smoothed to avoid clicks.
- Tap Stop when you're done, or just navigate away — the oscillator is always released on Stop or on leaving the page.
FAQ
- Is this a pure tone, and can I trust the frequency?
- Yes — the sine waveform is a single oscillator frequency with no harmonics, generated directly by the Web Audio API's OscillatorNode, which is accurate to the sample rate. It's suitable as a genuine reference pitch.
- Why do frequency changes fade instead of jumping instantly?
- An instant frequency or volume jump on a live oscillator produces an audible click or pop. Changes are applied with a short exponential ramp instead, so you can sweep or nudge the pitch smoothly while it's playing.
- What does the oscilloscope actually show?
- It reads the oscillator's real output through an AnalyserNode and redraws the exact waveform shape every animation frame — when you switch from sine to square, you're watching the actual signal change, not an illustration of one.
- What frequency range is available?
- 20 Hz to 5000 Hz by direct entry or slider, and the note dropdown covers C0 through B8 — well beyond any acoustic instrument's fundamental range.
