Choose a Frequency
Enter an exact Hz value, move the logarithmic slider, use a preset, or step by one hertz or one octave.
Tone 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
Online Tone Generator
Generate a controlled digital audio signal in your browser, inspect its basic properties, route it in stereo, or save a short WAV file without uploading audio anywhere.
What Is an Online Tone Generator?
An online tone generator creates a repeating digital waveform at a frequency you choose. Frequency is entered in hertz, meaning cycles per second: a 440 Hz setting asks the oscillator to complete 440 cycles each second. This tool uses the browser Web Audio API and starts only after you press Play. It is useful when you need an immediate reference signal without installing a synthesizer or sending a file to a server.
The main controls cover 20 Hz to 20 kHz on a logarithmic slider because equal distances on that scale better reflect how octaves are arranged. The numeric field also accepts technically safe values from 1 Hz to 22,000 Hz, subject to the audio device sample rate. The online tone generator then reports the period, nearest equal-tempered musical note, cents offset, and an approximate wavelength in air at 20°C. Those calculations describe the intended signal; they do not certify what a speaker produces.
Three simple steps
How to Get Started
Use this online tone generator deliberately: set the signal, begin quietly, and interpret only what the workflow can actually show.
Select a Waveform and Start Low
Choose sine, square, triangle, or sawtooth. Keep the output level conservative before pressing Play.
Play, Adjust, Test, or Export
Make smooth live changes, compare stereo channels, inspect the waveform, share settings, or create a local WAV.
What Can You Use a Tone Generator For?
A tone generator can provide an A4 pitch reference at 440 Hz, a 1 kHz signal for tracing an audio path, or a low tone around 40–60 Hz for a cautious bass check. Moving the balance from left to right can reveal a routing mistake, disconnected cable, or unexpected channel swap. Teachers can demonstrate how frequency changes pitch, while musicians can compare intervals without needing a recorded sample.
These are observations, not calibrated tests. If 10 kHz seems quiet, the cause could be your speaker, headphones, operating-system processing, room, listening position, or hearing. The online tone generator supplies a known numerical input to that chain; it does not isolate every link. For a tone that changes over time, use the frequency sweep generator. For simultaneous signals, use the multiple tone generator.
Sine, Square, Triangle, and Sawtooth Waves
A sine wave contains one fundamental sinusoidal component in the generated digital signal, so it is the cleanest starting point for pitch references and simple checks. Square, triangle, and sawtooth signals contain additional harmonics. They sound brighter because energy appears at multiples of the fundamental frequency. At high settings, some harmonics would exceed the playback sample rate and cannot be represented normally.
Waveform choice changes timbre even when frequency stays fixed. A 440 Hz sine and a 440 Hz square share the same fundamental pitch but do not have the same spectrum or perceived character. Begin with sine unless the harmonics are part of the lesson or test. The dedicated sine wave generator locks the signal shape and provides a workflow centered on pure tones.
Understanding Frequency and Pitch
Frequency is a physical rate, while pitch is a human perception that usually follows frequency but is influenced by level, timbre, context, and the listener. Doubling frequency moves up one octave in twelve-tone equal temperament. That is why 440 Hz is A4 and 880 Hz is A5. The ÷2 and ×2 controls make this relationship easy to hear with the online tone generator.
Period is the duration of one cycle. At 1 kHz the period is 1 millisecond; at 440 Hz it is about 2.273 milliseconds. The displayed note and cents value are calculated from A4 = 440 Hz. They help relate frequency to musical notation, but the site is not measuring an instrument through a microphone and therefore is not acting as a tuner.
Why Your Device May Not Reproduce Every Frequency
A browser can request a very low or high oscillator frequency even when the connected transducer cannot reproduce it usefully. Small laptop and phone speakers often roll off deep bass. High-frequency output may be reduced by headphones, speakers, digital processing, or sample-rate limits. Human sensitivity also varies, especially toward the edges of the commonly cited audible range.
Do not turn the volume up sharply to chase a tone you cannot hear. Low-frequency energy can stress small drivers, and high tones can become uncomfortable before they seem subjectively loud. Try a moderate reference such as 440 Hz or 1 kHz to confirm that playback works. Then move gradually, stopping immediately if anything buzzes, strains, or feels unpleasant.
Digital Level Is Not the Same as Sound Pressure Level
The output percentage controls gain inside the browser. It has no direct conversion to dB SPL at your ears. Actual acoustic level depends on the computer or phone volume, DAC, amplifier, transducer sensitivity, distance, room, and other gain stages. Fifteen percent in this online tone generator can therefore produce very different loudness on two systems.
A calibrated sound-level meter or measurement microphone is needed when acoustic level matters. Even then, the full measurement setup must be calibrated. Use the percentage only as a repeatable setting within the current browser session, begin low, and regard listening comparisons as subjective checks rather than measurements of absolute output.
Common Tone Generator Users
Musicians use reference tones to compare pitch or tune by ear. Audio hobbyists trace channels and look for obvious buzzes. Students explore cycles, period, wavelength, octaves, and harmonics. Developers can confirm that browser audio reaches a selected output. Electronics learners may use a generated WAV as a simple known input, provided the receiving equipment can safely accept the connected signal.
The online tone generator is deliberately a general-purpose starting point. A frequency generator puts exact Hz work first; a test tone generator adds timed playback and channel-oriented presets; the speaker and subwoofer tests provide guided sequences. Choosing the narrowest tool reduces setup and makes the limitations for that task clearer.
Tone Generator Safety
Tone generator safety begins with conservative output and short listening periods. Steady tones concentrate energy and can be tiring or harmful when played loudly or for too long. Set both the device volume and tool level low before starting, avoid holding headphones tightly against your ears while experimenting, and stop at the first sign of discomfort. Never use a barely audible result as a reason to make a sudden large level increase.
This online tone generator is not a hearing test and cannot diagnose a person or a playback device. Protect equipment as well as hearing: strong low tones may cause excessive driver movement, while square and sawtooth waves contain substantial harmonic energy. You are responsible for suitable levels, connections, equipment, and surroundings. See the full disclaimer for details.
Clear answers
Frequently Asked Questions
What frequency can this online tone generator produce?
The numeric control accepts 1 Hz through 22,000 Hz, but playback is also kept strictly below the runtime Nyquist limit. The main logarithmic slider focuses on 20 Hz through 20 kHz. A selected value does not guarantee that your playback hardware can reproduce it.
Why can’t I hear very low or very high frequencies?
The speaker, headphones, gain chain, processing, room, and listener can all limit audibility. Confirm playback at a moderate frequency and never raise volume abruptly to compensate for an inaudible edge-of-range tone.
Is 440 Hz the note A4?
Yes, in twelve-tone equal temperament referenced to A4 = 440 Hz. The note display is a mathematical conversion of the generated value, not a microphone-based tuning measurement.
Can I download a tone as WAV?
Yes. Select a duration and use Export WAV. The file is encoded locally as PCM in your browser and does not require an upload.
Does the output percentage equal decibels?
No. It is a digital gain control, not calibrated dB SPL. Acoustic sound level depends on the entire playback system and environment.
What are the basics of tone generator safety?
Good tone generator safety means beginning quietly, keeping tests brief, avoiding sudden level increases, and stopping immediately when a signal causes discomfort or equipment strain.