Online Tone Generator

A free online tone generator and frequency generator

This free online tone generator plays precise test tones in your browser. It is also a frequency generator: type any value from 1 Hz to 20,000 Hz, pick a waveform, watch the live preview, and download WAV audio without installing software.

Common targets include a 440 Hz A4 tuning tone, a 432 Hz alternative reference, a 1 kHz alignment tone, bass checks near 40–100 Hz, and high-frequency checks at 10–15 kHz. Choose sine for a pure tone, or square, triangle, or sawtooth when you want harmonics.

Everything you hear is synthesized on this page after you press Play or start a sweep. The tool does not open the microphone, does not record you, and does not upload audio. Acoustic results still depend on your browser, operating system, and headphones or speakers.

What can you use this tone generator for?

A browser tone generator is useful whenever you need a known pitch without installing desktop software. Typical jobs:

Why use this free frequency generator

Many online tone generators stop at a slider and Play. This page is built for quick testing and precise control without leaving the browser.

Sine, square, triangle, and sawtooth waveforms

Frequency sets the pitch. Waveform sets how that pitch is shaped. A sine wave generator is the right choice when you want one clean frequency. The other three are useful when you want to hear harmonics.

How to use this online tone generator

1. Set a low volume. Start near the bottom of the volume slider, especially with headphones. Stop playback immediately if you experience discomfort. The control is a relative level inside the browser, not a calibrated decibel measurement.
2. Choose a frequency. Type a value from 1 to 20,000 Hz, move the logarithmic slider, use octave or fine-step buttons, or tap a quick preset.
3. Select a waveform. Sine is a pure tone. Square, triangle, and sawtooth add harmonics, so they sound brighter or buzzier at the same frequency.
4. Press Play or run a sweep. Use Tone mode for a steady pitch, or Sweep mode to glide between two frequencies. Nothing plays until you press Play or Start sweep. Frequency, waveform, and volume can change while audio is running.
5. Download or share. Use Download WAV in the toolbar, or open More for duration and channel options. Share and Copy link store frequency, waveform, volume, and duration without starting audio.

Hertz, frequency, and pitch explained

Hertz (Hz) counts cycles per second. A 440 Hz sine completes 440 cycles each second and, in standard tuning, is the note A4. Double the frequency and the pitch rises one octave: 880 Hz is A5 when A4 is 440 Hz. Halving it drops one octave.

This page names the nearest note with 12-tone equal temperament. Cents measure how far the entered frequency sits from that note. One hundred cents equal one semitone. A reading of 0.0 cents means the frequency matches the note at the current A4 reference. The default reference is 440 Hz. Setting it to another value between 400 Hz and 480 Hz, such as 432 Hz, relabels the notes without retuning the oscillator.

Human hearing is often described as roughly 20 Hz to 20,000 Hz, but that range is not a promise. Low frequencies need excursion from a speaker or headphone. High frequencies are the first to disappear with age, listening level, and consumer drivers. A phone speaker that is silent at 40 Hz can still be working.

Output depends on your device, driver, and headphones or speakers. This is not a calibrated sound-pressure level, and not every device can reproduce 1 Hz or 20,000 Hz. The slider is logarithmic: equal movement corresponds to a similar ratio, not a similar number of hertz. That keeps 40 Hz and 10,000 Hz both within easy reach. The ± buttons and the number field are linear, so they are the better tools when you already know the exact pitch.

• What is a tone generator?

  A tone generator plays a tone at a frequency you choose, measured in hertz (cycles per second). This online tone generator builds that tone in your browser with the Web Audio API, so you can compare waveforms, watch a live preview, and save a WAV file without installing software.

• What is a frequency generator?

  A frequency generator is the same idea with emphasis on choosing an exact Hertz value. On this page you can type any frequency from 1 Hz to 20,000 Hz, use presets such as 440 Hz or 1 kHz, or sweep between two frequencies.

• How do I generate a specific frequency?

  Enter the frequency in hertz, move the slider, use octave or fine-step buttons, or choose a preset, then press Play. Decimals such as 440.5 are allowed. The large readout, the slider, and the musical-note line all follow the same value.

• What is the difference between sine and square waves?

  A sine wave is a single frequency and sounds smooth. A square wave switches between two levels and adds odd harmonics, so it sounds hollower and brighter. A triangle wave also has odd harmonics, but they fall away faster. A sawtooth wave contains both odd and even harmonics and sounds buzzy. The frequency stays the same when you change waveform; the harmonic content changes.

• Can I generate 440 Hz?

  Yes. 440 Hz is the standard A4 concert pitch. Choose the 440 Hz preset or type 440 and press Play. With the A4 reference left at 440 Hz, the note display reads A4 and about 0 cents.

• Can I generate 432 Hz?

  Yes. Type 432 or choose the 432 Hz preset. You can also set the A4 reference to 432 Hz if you want note names calculated from that tuning. Changing the reference only changes the note and cents display. The tone you hear changes only when the frequency itself changes.

• Is an online tone generator safe for my ears and speakers?

  Start at low volume, especially with headphones and frequencies above about 8 kHz. Pure tones concentrate energy at one frequency and can feel louder or more fatiguing than music at the same slider position. Stop immediately if anything is uncomfortable. This page also asks for a second confirmation before very loud or very high playback in a session.

• Can I download a WAV file?

  Yes. Press Download WAV in the toolbar, or open More to choose a duration from 0.5 to 30 seconds, 44.1 kHz or 48 kHz, and mono or stereo. The file is 16-bit PCM rendered locally with the frequency, waveform, and volume you selected. Stereo writes the same tone to both channels. The file is not uploaded.

• Does this tool require a microphone?

  No. The generator only creates sound. It does not request microphone permission, record the room, or send audio to a server.

• Does the tone generator work offline?

  After the page has loaded, tones are synthesized locally with the Web Audio API. You do not need to upload files. A full offline visit still depends on your browser keeping the page cached.

• Can I use the generator on mobile?

  Yes, in current Chrome, Safari, Firefox, and Edge on phones and tablets. Mobile browsers block sound until you tap Play. Use a low volume with earbuds, and use the numeric field if the slider is awkward. A sticky Play control stays available while the generator is on screen.

• Why can't I hear certain frequencies?

  Hearing and hardware both have limits. Very low tones need speakers that can move air; phone speakers are often weak below about 150 Hz. Very high tones approach the limit of human hearing, which commonly drops with age, and many devices filter them. Silence at 20 Hz or 20,000 Hz usually means the equipment or your hearing cannot reproduce that tone, not that the oscillator failed. This page cannot measure what actually left the speaker.

• Can I use it to test speakers?

  Yes, as an informal listening check. Presets and the frequency sweep help you hear whether a headphone or speaker produces low, mid, and high tones. It is not a calibrated measurement, a room analysis, or a hearing test, and it does not report sound-pressure level.

• How accurate is the frequency?

  The oscillator is set to the Hertz value you enter, within the limits of the Web Audio API and your device clock. What you hear can still differ if the speaker cannot reproduce that pitch cleanly, or if the system resamples audio. This page is a listening and reference tool, not a laboratory calibrator.