Set the Sine Frequency
Enter an exact value, move the logarithmic slider, or start with the 440 Hz and 1 kHz shortcuts.
Pure sine workspaceLocal audio
Ready — sound is off
Hz
Quick frequencies
Frequency440 Hz
Period2.273 ms
WaveformSine
Nearest noteA4 · +0 cents
Wavelength at 20°C≈ 78.0 cm
Browser audio signal toolkit
Sine Wave Generator
Create one sinusoidal digital frequency with fine pitch, level, and stereo control, then inspect its period and waveform or export a timed local WAV.
What Is a Sine Wave Generator?
A sine wave generator produces a smooth periodic signal described by a sinusoidal function. You choose the number of cycles per second in hertz, and the browser schedules that frequency through Web Audio after you press Play. This page locks the oscillator to sine so the workflow stays focused on single-frequency reference tones rather than general waveform design.
The exact frequency field accepts values from 1 Hz to 22,000 Hz when they are also below the active sample rate’s Nyquist limit. A logarithmic slider covers the practical 20 Hz–20 kHz workspace, and fine-step buttons make close comparisons straightforward. The sine wave generator displays a live time-domain trace from an AnalyserNode plus calculated period, nearest note, cents offset, and approximate wavelength in air.
Three simple steps
How to Get Started
Use this sine wave generator deliberately: set the signal, begin quietly, and interpret only what the workflow can actually show.
Lower the Listening Level
Choose a stereo position and set both your device and the digital output conservatively before playback.
Play or Export the Pure Tone
Listen briefly, inspect the real signal trace and calculations, or choose a duration for local WAV export.
Why a Sine Wave Is Often Called a Pure Tone
In this tool, “pure tone” means that the digital source contains one sinusoidal frequency rather than the harmonic series intentionally produced by square, triangle, or sawtooth shapes. A 1 kHz sine signal is therefore a useful simple reference. The phrase describes the generated data, not a guarantee that the acoustic wave reaching your ears contains no distortion, noise, or reflections.
Playback hardware is never ideal. DAC filtering, amplifier noise, driver distortion, operating-system processing, and the room can add or alter spectral content. The sine wave generator does not measure those effects. If you need to verify purity after playback, you need suitable capture hardware and analysis, with calibration appropriate to the quantity being measured.
Sine Wave Frequency and Period
Frequency counts complete cycles per second, and period measures the time for one cycle. They are reciprocals. A 500 Hz sine has a 2 ms period, a 1 kHz sine has a 1 ms period, and a 10 kHz sine has a 0.1 ms period. The live information panel updates this calculation whenever the selected frequency changes.
The note display translates frequency into twelve-tone equal temperament with A4 fixed at 440 Hz. It is helpful when connecting an audio sine wave to musical pitch: 440 Hz maps to A4, and 880 Hz maps to A5. The cents result shows the difference from the nearest equal-tempered note. This is computed from the selected setting rather than measured from a microphone.
Common Uses for Sine Tones
Sine tones can provide a pitch reference, reveal whether an audio path is connected, demonstrate frequency and phase concepts, or supply a controlled input for a simple experiment. A teacher might compare 250 Hz and 500 Hz to demonstrate an octave. A musician might use 440 Hz as an A reference. An audio hobbyist might route 1 kHz to the left and right channels separately.
A sine wave generator also helps with cautious subjective checks at different frequencies because its source signal does not intentionally add harmonics. If you are checking a wide range, a frequency sweep is faster than selecting isolated points. If you want repeatable timed signals for a workflow, the test tone generator adds duration presets and a dedicated channel setup.
Sine Waves vs Square, Triangle, and Sawtooth Waves
A square wave contains odd harmonics with relatively strong upper components, a triangle wave contains odd harmonics that fall away more quickly, and a sawtooth includes both even and odd harmonics. Those extra components give each shape its recognizable timbre. A sine wave generator intentionally avoids selecting among them so there is no ambiguity about the requested source shape.
At the same fundamental frequency, these waveforms can differ substantially in peak behavior, spectral energy, and perceived loudness. Comparing them at one percentage setting is not a controlled loudness comparison. Use the general online tone generator when waveform contrast is the goal, and lower the output before changing from sine to a harmonically richer signal.
What the Browser Generates vs What Your Speaker Produces
The browser creates samples and sends them into the operating system’s audio path. From there, sample-rate conversion, effects, volume controls, DAC behavior, amplification, and transducer limitations can all change the result. The sine wave generator knows the requested digital frequency and gain but has no microphone feedback and no calibrated knowledge of sound pressure in the room.
This distinction matters at the edges of the range. A laptop may accept a 30 Hz signal while producing little meaningful deep bass, and some systems may attenuate high frequencies. The absence of an audible tone does not identify which stage is responsible. Confirm basic playback around 440 Hz or 1 kHz, move gradually, and use measurement equipment when quantitative results matter.
Common Users: Audio Testing, Education, Music, Electronics
Students use a sine wave generator to connect equations with a visible and audible cycle. Musicians use pure tones as pitch references or interval examples. Audio users employ them while tracing a channel or listening for obvious rattles at a specific frequency. Electronics learners may export a WAV for use as a known digital file, provided every physical connection and input level is suitable.
Professional acoustic or electrical work requires more than a browser source. Formal testing typically defines tolerance, calibration, signal level, load, measurement bandwidth, and uncertainty. This tool does not claim those capabilities. Its strength is immediate local generation, transparent settings, useful calculations, and conservative controls for preliminary checks and demonstrations.
Safe Listening With Pure Tones
A simple tone can be more fatiguing than complex program material because its energy remains concentrated. Start with the sine wave generator level low and the system volume reduced. Use short listening periods. Stop immediately if you feel discomfort, pressure, or ringing, and never turn the level up quickly because a low or high setting seems inaudible.
The tool cannot diagnose hearing or certify speaker performance. Sensitivity varies among people and devices, and loud or prolonged exposure can be harmful. Be especially cautious with headphones and low-frequency tests that may cause excessive driver movement. The output percentage represents browser gain only; it does not state or estimate dB SPL at the listener.
Exporting a Sine-Wave WAV
Choose a one-, three-, five-, ten-, or thirty-second duration and press Export WAV. The sine wave generator encodes a stereo PCM file locally, applies the selected digital level and pan, and uses short edge envelopes to reduce discontinuities at the start and end. No audio data is uploaded, and playback is not required for export.
The filename records the selected frequency, waveform, and duration. The file is a convenient test asset, not a calibrated master. A media player may apply volume, equalization, or other processing, and the output device remains subject to its own limitations. Keep the same caution when playing the file elsewhere.
Clear answers
Frequently Asked Questions
Is a sine wave the same as a pure tone?
In this context, a pure tone means a single sinusoidal digital frequency. Real playback can add noise, distortion, reflections, and other changes, so the acoustic result is not guaranteed to remain spectrally pure.
Why is waveform selection locked?
This page is intentionally a sine wave generator. Locking the waveform keeps the setup unambiguous; the main tone generator is available when you want square, triangle, or sawtooth signals.
Can I use 440 Hz as an A note reference?
Yes. With the displayed A4 = 440 Hz convention, 440 Hz maps to A4. It is a generated reference, not a measurement of an instrument.
Can the generator measure speaker distortion?
No. It creates a source signal but does not record or analyze speaker output. Distortion measurement needs appropriate capture and analysis equipment.
Does WAV export send audio to a server?
No. The PCM file is generated and downloaded locally in the browser.