Online Tone Generator

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Generate precise audio tones from 20 Hz to 20 kHz. Adjust frequency, waveform, volume, and stereo pan. Download as WAV file.Learn more ▾Show less ▴
This tone generator produces precise audio frequencies from 20 Hz to 20,000 Hz directly in your browser. Choose from six waveforms — sine, square, triangle, sawtooth, white noise, and pink noise — and fine-tune every parameter in real time.
  • Play any frequency with Hz input or musical note selection across the full chromatic range (C0–B8), with presets for A440 concert pitch, Solfeggio frequencies, and test tones
  • Sweep mode glides between two frequencies using logarithmic or linear curves — presets cover full-range hearing tests, bass, treble, and ultrasonic ranges
  • Five generator modes: single tone, dual tone, amplitude/frequency modulation, rhythmic burst patterns, and pulse sequences
  • Export any sound as a WAV file (1–60 seconds) for testing, music production, or sound therapy
  • Real-time waveform visualization with adjustable volume, stereo panning, and built-in hearing safety warnings
All processing runs locally in your browser — your audio is never uploaded or recorded.
20 Hz 20 kHz
Hz
A4 +0 cents 440 Hz
100 Hz
8000 Hz
20%
Stereo & fade
Center
50 ms

Two tones

Generate two independent tones simultaneously. Create beat frequencies by setting slightly different frequencies.

Hz
Hz
Beat Frequency?The difference in frequency between the two oscillators, perceived as a rhythmic pulsation (binaural beat). 5 Hz
1 2

Modulation

Apply AM (amplitude) or FM (frequency) modulation to create complex tones and warble effects.

?AM varies the volume. FM varies the pitch.
Hz
Hz
50%

Burst

Generate tone bursts with customizable envelope shapes, duration, and repeat intervals.

Hz
100 ms
500 ms
5

Pulse

Create windowed pulse trains for transient response testing and signal analysis.

Hz
10 Hz
10%
?Show a real-time waveform display of the generated audio.
—Hz —ms Silent

Download WAV
seconds

Settings
0 dBFS
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About This Tool

Generate precise audio tones from 20 Hz to 20,000 Hz using the Web Audio API (W3C). Choose from four waveforms—sine (pure tone), square (hollow), triangle (soft), and sawtooth (bright)—and adjust frequency with a logarithmic slider or precise Hz input. Control volume and stereo panning, view the nearest musical note with cents deviation based on the A4 = 440 Hz standard (ISO 16:1975), and export tones as uncompressed WAV files at sample rates from 44.1 kHz to 192 kHz. All processing runs locally in your browser—no data is sent anywhere.

Sources: Wikipedia · MDN

How to Use

  1. Set your desired frequency using the slider or enter a specific value in Hz. Choose from preset frequencies or fine-tune with +/- buttons.
  2. Select a waveform type (sine, square, sawtooth, or triangle) and adjust volume and stereo pan controls to customize your tone.
  3. Press Play to hear your tone and watch its waveform in real-time. Download it as a WAV file for offline use.

How to Use

  1. Set your desired frequency using the slider or enter a specific value in Hz. Choose from preset frequencies or fine-tune with +/- buttons.
  2. Select a waveform type (sine, square, sawtooth, or triangle) and adjust volume and stereo pan controls to customize your tone.
  3. Press Play to hear your tone and watch its waveform in real-time. Download it as a WAV file for offline use.

Methodology

This tone generator uses the Web Audio API's OscillatorNode for mathematically precise waveform generation at frequencies from 20 Hz to 20 kHz. Each waveform has a distinct harmonic profile: sine waves contain only the fundamental frequency (the purest tone), square waves contain odd harmonics (1st, 3rd, 5th…) creating a hollow sound, triangle waves also contain odd harmonics but at lower amplitudes producing a softer timbre, and sawtooth waves contain all harmonics giving the brightest, richest sound. The logarithmic frequency slider maps human pitch perception accurately—we perceive the interval between 100 Hz and 200 Hz as the same 'distance' as 1,000 Hz to 2,000 Hz (both are one octave). Musical note detection uses the A4 = 440 Hz standard with 12-tone equal temperament (12-TET), where each semitone is exactly the 12th root of 2 (≈ 1.05946) times the previous. Cents deviation is calculated as 1200 × log₂(f/fnearest), where ±50 cents spans one semitone. Volume control uses a GainNode with logarithmic scaling matching the decibel scale. Stereo panning uses a StereoPannerNode for smooth left-right positioning. WAV export renders the oscillator output to an OfflineAudioContext, creating uncompressed PCM audio at sample rates from 44.1 kHz (CD quality) to 192 kHz (studio/archival quality).

Sources: MDN Web Audio API · Wikipedia: Audio Frequency

Understanding Your Results

Sine waves produce the purest, most fundamental tone—ideal for tuning instruments, hearing tests, and scientific calibration. They contain no harmonics, making them the building block of all other sounds through Fourier synthesis. Square waves sound hollow and buzzy, resembling early video game audio and analog synthesizers. They're useful for testing speaker response and creating retro electronic sounds. The sharp transitions between on/off states make them ideal for digital signal testing. Triangle waves sound softer and warmer than square waves while retaining a slightly electronic quality. They're commonly used in synthesizer bass sounds, flute-like tones, and subtle sub-bass frequencies in music production. Sawtooth waves are the brightest and richest, containing every harmonic. They form the basis of many synthesizer lead sounds, brass emulations, and string patches. Their full harmonic content makes them ideal for subtractive synthesis, where filters shape the raw tone. For frequency reference: A4 = 440 Hz is the international tuning standard. Concert pitch ranges from A0 (27.5 Hz) to C8 (4,186 Hz). Sub-bass frequencies (20–60 Hz) are felt more than heard, while frequencies above 15 kHz become inaudible with age.

Sources: NASA: Science of Sound · Britannica: Sound Physics

Practical Examples

A music producer uses the sine wave at 440 Hz to verify their studio monitors are accurately reproducing pitch, then switches to sawtooth to test the full frequency response across the harmonic spectrum. An audiologist generates a series of sine tones from 250 Hz to 8 kHz at controlled volumes to create a basic hearing screening test for educational demonstrations. A sound designer exports a 60 Hz sawtooth wave as WAV, then imports it into their DAW to use as the foundation for a synthesizer bass patch, applying filters and effects to shape the final sound.

Tips for Using the Tone Generator

Always start at low volume and increase gradually—prolonged exposure to loud tones can damage hearing. The safety warning appears for a reason. Use the sine waveform for instrument tuning and hearing tests, as it produces only the fundamental frequency without harmonics that could confuse pitch detection or mask hearing loss at specific frequencies. The logarithmic slider is more intuitive for musical work since pitch perception is logarithmic. For precise frequencies, type the exact Hz value into the input field—useful for scientific applications or targeting specific musical notes. When testing speakers or headphones, sweep slowly from 20 Hz to 20 kHz with a sine wave. Note where sound becomes inaudible at both ends to understand your equipment's frequency range and your personal hearing limits. For WAV export, 44.1 kHz sample rate is sufficient for most uses. Choose 96 kHz or 192 kHz only for professional studio work or when you need to preserve ultrasonic content above 22 kHz. Use stereo panning to test left-right speaker balance. A centered tone should appear equally loud in both ears with properly calibrated equipment.

Sound Science Facts

  • Human hearing spans 20 Hz to 20,000 Hz, but perception is logarithmic—we're most sensitive around 4 kHz, where speech clarity resides.
  • Sound intensity follows the inverse square law: doubling your distance from a source reduces intensity by 75% (a 6 dB drop).
  • Unlike matter, an infinite number of sound waves can occupy the same space simultaneously—this is the superposition principle that enables orchestras and conversations.
  • The Web Audio API generates tones mathematically using oscillators, supporting sine (pure), square (hollow), triangle (soft), and sawtooth (bright) waveforms.
  • Sound travels as longitudinal (compression) waves. The speed depends on the medium and temperature—about 343 m/s in air at 20°C, but 1,480 m/s in water.

Sources

All calculations are performed locally in your browser. No data is sent to any server.

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Space: Play/Stop. Arrow Up/Down: Adjust frequency. Arrow Left/Right: Adjust pan. R: Reset.
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Frequently Asked Questions
What can I use this tone generator for?
Common uses include: tuning musical instruments to standard pitch (A440), testing audio equipment and speakers across frequency ranges, calibrating recording setups, conducting hearing tests and frequency identification, using Solfeggio frequencies for meditation and relaxation, scientific experiments with frequency and waveforms, physics education demonstrations of sound waves, and creating reference tones for music production.
What is the difference between Continuous and Tap Once modes?
Continuous mode plays the tone indefinitely until you click Stop—perfect for extended testing, tuning instruments, or meditation. Tap Once mode plays for a set duration (0.1 to 15 seconds) then automatically stops—ideal for quick frequency identification, A/B comparisons, or precise timing needs. Choose shorter durations (0.1-0.5s) for rapid testing, medium durations (1-3s) for comfortable listening, or longer durations (10-15s) for extended evaluation.
What are Solfeggio frequencies?
Solfeggio frequencies are specific tones believed by some to have healing or meditative properties: 396 Hz (liberation from fear), 417 Hz (facilitating change), 528 Hz (transformation and DNA repair), 639 Hz (connecting relationships), 741 Hz (expression and solutions), and 852 Hz (spiritual awakening). While scientific evidence for their therapeutic effects is limited, many people use them for meditation and relaxation.
Is it safe to use high frequencies or loud volumes?
Always start at low volume (below 25%) and gradually increase if needed. High frequencies above 10 kHz can be uncomfortable and potentially harmful, especially at high volumes. Never exceed 50% volume for extended periods. People with hearing sensitivity, tinnitus, or ear conditions should consult a doctor before using tone generators. If you experience discomfort, ringing, or pain, stop immediately.
What is the difference between waveforms?
Sine waves produce pure, smooth tones with a single frequency—ideal for precise tuning and testing. Square waves sound electronic and buzzy with many harmonics. Triangle waves are mellower than square but richer than sine. Sawtooth waves are bright and rich with all harmonics. White noise contains all frequencies equally—useful for speaker testing. Pink noise emphasizes lower frequencies—closer to natural sounds. Brown noise has even deeper bass emphasis with a rumbling quality—often used for sleep and relaxation.
How do I export a tone as a WAV file?
Click the 'Export WAV' button to download your tone as an audio file. You can select a custom duration from 1 to 60 seconds before exporting. The file downloads automatically to your device and can be used in audio editing software, as a ringtone, or for any other purpose. The exported file is in standard WAV format (44.1 kHz, 16-bit) compatible with all audio software.
Can I use this for tinnitus frequency matching?
Yes, many people use tone generators to identify their tinnitus frequency. Start at low volume and gradually adjust the frequency until it matches the ringing you hear. Most tinnitus falls between 2-8 kHz. Once identified, this information can help your audiologist provide better treatment. However, this tool is not a medical device—always consult a healthcare professional for tinnitus management.
What is the 40 Hz tone used for in Alzheimer's research?
Recent research from MIT suggests that 40 Hz light and sound stimulation may help reduce amyloid plaques in the brain, which are associated with Alzheimer's disease. Studies on mice showed promising results, and human trials are ongoing. While this is an exciting area of research, it's still experimental. This tool provides the 40 Hz frequency for educational and experimental purposes, but it should not be considered a medical treatment.
What is Sweep Mode and how do I use it?
Sweep Mode plays a continuous frequency sweep from a start frequency to an end frequency over a set duration. Click the 'Sweep' tab to access it. Set custom start/end frequencies (20 Hz to 20 kHz), duration (0.1 to 60 seconds), and choose between logarithmic (natural to human hearing) or linear sweep types. Use preset ranges like Full (20-20k Hz), Bass (20-250 Hz), Mid (250-4k Hz), Treble (4k-20k Hz), or Sub (20-80 Hz). Sweep mode is ideal for speaker testing, finding resonance frequencies, and hearing range assessment.
What does the Fade control do?
The Fade control (0-500 ms) sets how quickly the tone fades in when you press Play and fades out when you press Stop. A value of 0 ms means instant on/off, which can cause audible clicks. Higher values (50-200 ms) create smoother, more pleasant transitions. The default 50 ms provides a good balance between responsiveness and smoothness. This applies to both Generator and Sweep modes.
What is the difference between 432 Hz and 440 Hz tuning?
The international standard concert pitch (ISO 16:1975) defines A4 as 440 Hz, and virtually all modern instruments and orchestras tune to this reference. 432 Hz is an alternative tuning where A4 is set 8 Hz lower. Some listeners describe 432 Hz as sounding warmer or more natural, though controlled studies have not found consistent measurable differences in listener preference. Historically, tuning standards varied widely—from around 415 Hz in the Baroque era to over 450 Hz in some 19th-century orchestras. You can compare both tunings using this tool and explore our 432 Hz guide for more detail.
How can I explore my hearing range with this tool?
Use Sweep mode to play a frequency sweep from 20 Hz to 20 kHz and notice where the sound fades out at both ends. The human hearing range is typically 20 Hz to 20 kHz for young adults, but the upper limit naturally decreases with age—most adults over 40 cannot hear above 15 kHz. You can also manually step through frequencies in Generator mode. Start at low volume and increase gradually. Note: this is an informal audio exploration, not a medical hearing evaluation. If you have concerns about your hearing, consult an audiologist.
What is brown noise and why is it popular for sleep?
Brown noise (also called Brownian or red noise) has a steep frequency roll-off that emphasizes deep, low-frequency rumbling—like a waterfall, strong wind, or distant thunder. Its power decreases by 6 dB per octave, making it deeper than pink noise (3 dB/octave) and much deeper than white noise (flat). Many people find it soothing for sleep and concentration because it masks higher-pitched environmental sounds effectively. To try it, select the Noise tab and choose Brown noise. You can export it as a WAV file for offline use.
Can I generate DTMF phone dial tones?
Yes. DTMF (Dual-Tone Multi-Frequency) signals are made of two simultaneous sine waves—one from a low group (697, 770, 852, 941 Hz) and one from a high group (1209, 1336, 1477, 1633 Hz). Use the Dual Oscillator mode to set both frequencies. For example, to generate the tone for digit 5, set Oscillator 1 to 770 Hz and Oscillator 2 to 1336 Hz with sine waveforms. See our DTMF guide for the complete frequency table for all keys (0-9, *, #, A-D).
What are isochronal tones and how do they differ from binaural beats?
Both are used for brainwave entrainment but work differently. Binaural beats require headphones—two slightly different frequencies are played in each ear (e.g. 200 Hz left, 210 Hz right) and the brain perceives a 10 Hz beat. Isochronal tones are a single tone pulsed on and off at a regular rate, creating a rhythmic beat that does not require headphones. You can create isochronal tones using the Pulse mode (set the pulse rate to your target frequency), and binaural beats using the Dual Oscillator mode with headphones. Scientific evidence for entrainment effects is still limited.
What is the Schumann resonance (7.83 Hz)?
The Schumann resonances are electromagnetic standing waves that exist in the cavity between Earth's surface and ionosphere, first predicted by physicist Winfried Otto Schumann in 1952. The fundamental mode is approximately 7.83 Hz, with harmonic modes at roughly 14.3, 20.8, 27.3, and 33.8 Hz. Since 7.83 Hz is far below the audible range (20 Hz minimum), you cannot hear it as a direct tone. However, you can experience it as a binaural beat by using Dual Oscillator mode with headphones—for example, 200 Hz in one ear and 207.83 Hz in the other. See our Schumann Resonance guide for more details.
What are the best frequencies for studying and focus?
Some people report improved focus using alpha-range binaural beats (8-14 Hz), which correspond to the brain's alert-but-relaxed state. To create a 10 Hz alpha beat, use Dual Oscillator mode with headphones and set frequencies like 200 Hz and 210 Hz. Gamma-range beats around 40 Hz are also studied for cognitive tasks. Alternatively, many find ambient noise helpful—pink noise or brown noise can mask distractions without demanding attention. Individual responses vary significantly, so experiment to find what works for you. Scientific evidence for frequency-based focus enhancement is still emerging.
What are binaural beats and how do I create them?
Binaural beats occur when two slightly different frequencies are played separately into each ear through headphones. Your brain perceives a third tone at the difference between the two frequencies. For example, 200 Hz in the left ear and 210 Hz in the right creates a perceived 10 Hz beat. To create them, switch to Dual Oscillator mode, set both waveforms to sine, then choose your two frequencies. Headphones are required—the effect does not work through speakers. Different beat frequencies correspond to brainwave bands: Delta (1-4 Hz, deep sleep), Theta (4-8 Hz, meditation), Alpha (8-14 Hz, relaxation), Beta (14-30 Hz, alertness), and Gamma (30-100 Hz, cognition).
What is the frequency sweep mode and how do I use it?
The Sweep tab lets you continuously glide from one frequency to another over a set duration. Choose start and end frequencies (e.g., 20 Hz to 20 kHz for a full hearing range test), pick logarithmic (perceptually even) or linear scaling, and set the sweep duration. Built-in presets include Full Range (20 Hz–20 kHz), Bass (20–250 Hz), Treble (4–20 kHz), Hearing Test (100 Hz–8 kHz), and Dog Whistle (15–20 kHz). Use it for speaker testing, hearing range assessment, audio equipment calibration, or finding resonant frequencies in a room.