Tone Generator
Generate precise audio frequencies from 20Hz to 20,000Hz using four waveform types: sine, square, triangle, and sawtooth. Adjust frequency with a slider and numeric input, control volume, and see the corresponding musical note name for any frequency. Features include adjustable A4 reference tuning (default 440Hz), optional binaural beat mode that plays slightly different frequencies in each ear for focus or relaxation, and frequency sweep mode for testing speaker response across the audible spectrum. Built on the Web Audio API for clean, artifact-free tone generation directly in your browser.
How to Use
- 1
Set the Frequency
Use the slider or number input to set any frequency between 20 Hz and 20,000 Hz. The current musical note name updates automatically — for example, 440 Hz displays as A4.
- 2
Choose a Waveform
Select sine for a pure tone, triangle for a softer sound, square for a hollow buzzy tone, or sawtooth for a bright, rich harmonic texture. Each waveform has a distinct character.
- 3
Adjust Volume and Play
Set the volume slider to a comfortable level, then click Play to start the tone. Click Stop to silence it. The tone plays continuously until stopped.
- 4
Tune A4 Reference
Adjust the A4 reference tuning slider (default 440 Hz, range 430-450 Hz) to match alternate tuning standards like A=432 Hz or A=443 Hz used by some orchestras.
Examples by Niche
Sweep from 20 Hz to 20,000 Hz to test your speakers or headphones across the full audible range. Identify dead spots or resonances in your monitoring setup.
Generate a steady 440 Hz sine tone as a tuning reference for your orchestra or ensemble. Adjust to 442 Hz if your group tunes higher for a brighter sound.
Slowly adjust the frequency until it matches the pitch of your tinnitus — useful for documenting the exact frequency to share with an audiologist.
Demonstrate how waveform shape affects timbre by switching between sine, square, triangle, and sawtooth at the same 440 Hz frequency. Students hear the harmonic differences instantly.
Frequently Asked Questions
What are the different waveform types used for?
Sine waves produce a pure, clean tone — ideal for tuning and hearing tests. Square waves have a hollow, buzzy quality used in chiptune music and synthesizers. Triangle waves sound softer than square waves with a flute-like character. Sawtooth waves are bright and harsh, commonly used as the basis for subtractive synthesis in analog synths.
What is binaural beat mode?
Binaural beat mode plays two slightly different frequencies in your left and right ears via stereo panning. Your brain perceives a third "beat" frequency equal to the difference. For example, 440Hz in the left ear and 444Hz in the right creates a 4Hz binaural beat. Headphones are required for the effect to work. Some users find specific frequencies helpful for focus or relaxation.
Can I use this to test my speakers or headphones?
Yes — use the frequency sweep mode to play tones across the full audible range (20Hz to 20kHz) and identify any dead spots or distortion in your speakers or headphones. This is a common technique used by audio engineers and audiophiles to evaluate frequency response without specialized equipment.
How is the musical note name calculated from a frequency?
The note name is derived using the formula: MIDI note = 12 * log2(frequency / 440) + 69. The integer part determines the note name (C, C#, D, etc.) and octave, while the fractional part shows how many cents sharp or flat the frequency is from the nearest equal-tempered note. A4 is defined as 440Hz by default but can be adjusted.
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