Sine Wave Generator Online — Free Pure Sine Tone Generator
Generate clean, pure sine waves online from 20 Hz to 20,000 Hz directly in your browser. Perfect for tuning instruments, testing audio gear, performing hearing tests, and running acoustic experiments — completely free, no signup required.
What is a Sine Wave?
A sine wave is the simplest and purest waveform in audio. It contains a single frequency with no harmonics or overtones, which is why it sounds smooth and clean. Sine waves are the mathematical foundation of all sound — every complex tone you hear can be decomposed into a sum of pure sine waves (a principle known as Fourier analysis).
Our online sine wave generator uses the browser’s native Web Audio API to synthesise mathematically perfect sine signals in real time, giving you a precise, distortion-free reference tone for any audio task.
Features of Our Sine Wave Generator
Pure Sine Output
Mathematically perfect sinusoidal waves with zero harmonic distortion — the cleanest tone possible for any audio reference work.
20 Hz – 20,000 Hz
Generate any sine frequency across the entire range of human hearing, in 1 Hz increments, for tuning, testing, and experiments.
Instant & Lightweight
Powered by the Web Audio API. No downloads, no plugins — start generating clean sine tones in under a second.
Calibration Ready
Use precise pure sine tones to calibrate speakers, headphones, subwoofers, mixers, and studio equipment.
Mobile Friendly
Runs flawlessly on iPhone, Android, tablets and desktops. Test any device, anywhere, anytime.
Hearing Safe
Built-in safety reminders. Always start at low volume — high-frequency sine waves can damage hearing at high SPL.
Common Uses for a Sine Wave Generator
Tune guitars, violins, pianos and brass to standard 440 Hz or alternative 432 Hz reference tones.
Test the frequency response of speakers, headphones and amplifiers using clean reference tones.
Sweep through frequencies to discover the limits of your hearing — especially the high end above 12 kHz.
Investigate resonance, beat frequencies, standing waves and acoustic phenomena in physics labs.
How to Use the Sine Wave Generator
1. Press Play
Click the Play button to start generating a pure sine wave instantly in your browser.
2. Set Frequency
Drag the slider or tap a preset to dial in your exact frequency from 20 Hz to 20 kHz.
3. Adjust Volume
Start low — pure sine tones can be louder than they feel. Increase gradually for safety.
4. Use the Tone
Tune, test, calibrate, or experiment — your sine wave plays continuously until stopped.
Sine Wave vs Square, Triangle & Sawtooth Waves
Unlike square, triangle and sawtooth waves — which contain rich harmonic content and sound buzzy or bright — a sine wave is a single pure frequency. This makes it the gold standard whenever a clean, neutral reference signal is needed: instrument tuning, speaker measurement, hearing thresholds, and acoustic research.
Sine
Pure, smooth, zero harmonics. The cleanest tone.
Square
Hollow, buzzy, rich in odd harmonics.
Triangle
Mellow, soft-edged, gentle harmonics.
Sawtooth
Bright, sharp, full harmonic content.
Frequently Asked Questions
Everything you need to know about online sine wave generation.
A sine wave is the simplest and purest waveform in audio. It contains a single frequency with no additional harmonics, which is why it sounds smooth and clean. Mathematically it is described by the sine function and is the fundamental building block of all other complex sounds.
A sine wave generator is used for tuning musical instruments (e.g., 440 Hz concert A), testing audio equipment and speakers, performing hearing tests, calibrating headphones, conducting physics and acoustics experiments, and generating reference tones for sound design.
Yes. Our online sine wave generator is completely free, requires no signup, no download, and no installation. It runs entirely in your browser using the Web Audio API for accurate, low-latency sine tone generation.
You can generate any sine wave frequency from 20 Hz (lowest range of human hearing) up to 20,000 Hz (the upper limit of human hearing) with 1 Hz precision.
A sine wave is a single pure frequency with no harmonics, producing a smooth, clean sound. Square, triangle, and sawtooth waves all contain additional harmonic content, which makes them sound harsher or more buzzy. Sine waves are ideal whenever you need a clean reference signal.
Yes, if played at high volumes — especially at very low or very high frequencies. Always start with low volume, particularly above 10 kHz or below 40 Hz. Prolonged exposure to loud pure tones can damage hearing and stress speakers and subwoofers.
440 Hz is the modern international standard for concert pitch (A above middle C). 432 Hz is an alternative tuning some musicians prefer for a warmer character. Both are popular sine wave reference frequencies for instrument tuning.
Yes. The sine wave generator works on iPhone, Android, tablets, and any modern browser that supports the Web Audio API, including Chrome, Safari, Firefox, and Edge.
Hearing Safety Warning
Pure sine waves can sound deceptively quiet but still carry significant energy. Always start at low volume — especially at frequencies above 10 kHz or below 40 Hz — to protect your hearing and your audio equipment.