An online tone generator is a web-based tool that produces pure audio tones at specific frequencies through your device's speakers or headphones. It uses the Web Audio API to generate precise sound waves in real-time. Our tool offers four waveform types — sine, square, sawtooth, and triangle — and covers the full human hearing range from 20 Hz to 20,000 Hz. It's commonly used for audio equipment testing, hearing checks, musical instrument tuning, scientific demonstrations, and meditation practices.

Sine Wave: The purest tone — smooth, clean, and free of harmonics. It's the fundamental building block of all sound.
Square Wave: Has a hollow, buzzy character rich in odd harmonics. Sounds similar to early video game music or a clarinet.
Sawtooth Wave: Bright and buzzy, containing both odd and even harmonics. This is the classic synth lead sound, reminiscent of violin or brass instruments.
Triangle Wave: Softer than a square wave but with more character than a sine wave. Contains only odd harmonics that decrease in amplitude more quickly, producing a mellow, flute-like tone.

The average human can hear frequencies from approximately 20 Hz (deep bass) to 20,000 Hz (very high treble). However, this range decreases with age — a condition known as presbycusis. Most adults over 25 may struggle to hear frequencies above 15-16 kHz. Our tone generator covers the full 20 Hz to 20,000 Hz spectrum, making it useful for testing your personal hearing range. Note: Listen at moderate volumes to protect your hearing.

440 Hz is the international standard pitch for the musical note A4 (the A above middle C). It's used as the reference tuning pitch for orchestras, bands, and most Western music. When you tune a guitar, piano, or violin, you're typically calibrating against A4 = 440 Hz. This standard was adopted by the International Organization for Standardization (ISO) in 1955 and remains the global reference for concert pitch.

Audio Equipment Testing: Check speaker frequency response, identify rattles or distortion.
Hearing Tests: Determine your personal hearing range by sweeping through frequencies.
Instrument Tuning: Use 440 Hz as a reference pitch for tuning guitars, violins, and other instruments.
Science & Education: Demonstrate sound wave properties, resonance, and beat frequencies in physics classrooms.
Meditation & Sound Therapy: Frequencies like 528 Hz are used in sound healing and meditation practices.
Pest Deterrence: High frequencies (15+ kHz) may deter certain pests like rodents or mosquitoes.

Always start at a low volume (we recommend 30-50%) and gradually increase. Prolonged exposure to loud sounds, especially at high frequencies, can cause permanent hearing damage. If you experience ringing in your ears (tinnitus) or discomfort, stop immediately. Keep in mind that frequencies above 10 kHz may be inaudible to some listeners — avoid cranking up the volume trying to hear them. Use headphones for more accurate frequency perception, but keep the volume moderate.

Hz (Hertz) is the unit of frequency, representing cycles per second. 1 kHz (kilohertz) = 1,000 Hz. So 5,000 Hz = 5 kHz. In audio, low bass sounds range from 20-200 Hz, midrange sounds from 200-2,000 Hz, and high treble sounds from 2,000-20,000 Hz (2 kHz to 20 kHz). Our tool displays frequencies in Hz for precision, but you'll often see kHz used in audio equipment specifications.