Tone Generator

What this tool does

Tone Generator produces precise test tones from 1 Hz to 24 kHz with the Web Audio OscillatorNode. Shift by semitones or octaves, sweep between two frequencies, play on the left or right channel only, generate white or pink noise and render any setting to a WAV file.

A clean, known frequency is the starting point for many practical jobs: tuning an instrument to A4 = 440 Hz, finding the rattle in a car door, checking which speaker in a surround set is wired to which channel, or testing how low a subwoofer really goes.

This generator uses the browser’s OscillatorNode, which produces mathematically exact waveforms at the frequency you type, and a short 10 ms fade at each end so tones start and stop without clicks. Sweeps glide between two frequencies on a logarithmic or linear curve. White noise uses the cryptographic random generator, and pink noise filters it to fall by 3 dB per octave so each octave carries equal energy. The same settings can be rendered offline to a WAV at 44.1, 48 or 96 kHz.

How to use Tone Generator

1. Pick a preset, or choose a Waveform: sine, square, sawtooth, triangle, white noise or pink noise.
2. Type the Frequency in Hz or drag the logarithmic slider; the note name and deviation in cents appear under the field.
3. Use the semitone and octave buttons to step the pitch, or switch on Frequency sweep and set the End frequency.
4. Set Volume (start low) and choose Both, Left only or Right only.
5. Click Play tone or Play sweep; changes apply while the tone is playing.
6. To save a file, set Duration and Sample rate under Export as WAV and click Render WAV.

Tips for better results

• Use a sine wave for tuning and hearing tests; square and sawtooth waves contain many harmonics and sound buzzy.
• A logarithmic sweep spends equal time on each octave, which matches how we hear pitch; a linear sweep rushes through the bass.
• Pink noise is the standard signal for balancing speaker levels by ear because it sounds even across the range.
• Above about 15 kHz many adults hear nothing at all, which is normal age-related hearing loss, not a fault.

Common use cases

• Tuning a guitar, violin or choir to A 440 Hz or another reference pitch.
• Checking left and right speaker wiring and finding buzzing or rattling panels with a slow bass sweep.
• Generating a 1 kHz reference tone for calibrating recording levels.
• Creating test files of known frequency for audio software or electronics projects.

Common mistakes to avoid

• Starting at full volume on headphones; loud high frequencies can damage hearing and small tweeters.
• Expecting small laptop speakers to reproduce 30 Hz; most cannot play much below 150 Hz.
• Confusing mains hum frequencies: the electricity grid runs at 50 Hz in Europe, India and most of Asia and Africa, and 60 Hz in North America.