Online Tone Generator
A Web Audio tone generator: set any frequency in hertz, choose sine, square, triangle or sawtooth, adjust volume and play precise test tones.
A sine wave is best for tuning and hearing tests. Keep the volume low on headphones, especially with high frequencies.
This online tone generator uses a Web Audio oscillator to produce a clean, steady tone at any frequency you choose. Set the pitch in hertz, pick a waveform, set the volume and press play. It is handy for tuning an instrument by ear, testing speakers and headphones, checking your hearing range or generating a reference pitch. Everything is synthesised in your browser.
Frequencies, waveforms and volume
Type any frequency between the deep sub bass around 20 Hz and the bright treble near 20,000 Hz, which spans the normal range of human hearing. A pure sine wave contains only the fundamental frequency and sounds smooth and flute like, which makes it the best choice for tuning references and hearing tests. A square wave sounds hollow and buzzy, a triangle wave is softer than a square but richer than a sine, and a sawtooth is bright and full of harmonics, close to the raw sound of a bowed string or a classic synth lead.
The volume control sets the output level. Start low, especially with headphones, because sustained tones can be fatiguing and loud high frequencies can be uncomfortable. The generator ramps the level up and down smoothly when you start and stop so you never hear a harsh click.
Preset test tones
The preset buttons jump straight to useful reference frequencies so you do not have to remember the numbers. A4 at 440 Hz is the standard concert pitch that orchestras and tuners around the world align to. 1,000 Hz is the classic reference used in audio equipment tests and loudness measurements. Lower presets around 100 Hz help you check whether a speaker or subwoofer reproduces bass cleanly, while higher presets let you probe the upper limit of your hearing. Use these tones alongside the chromatic tuner and note frequency chart to build a complete picture of pitch.
Frequently asked questions
What is a tone generator used for?
Common uses include tuning an instrument to a reference pitch, testing the frequency response of speakers and headphones, checking your hearing range, and producing a steady sine tone for audio experiments. The generator plays a precise, continuous tone at the frequency you set.
What is the difference between the waveforms?
A sine wave is the purest tone with no harmonics and sounds smooth. A square wave sounds hollow and buzzy, a triangle is softer and rounder, and a sawtooth is bright and rich. Sine is best for tuning and hearing tests, while the others are useful for timbre comparisons.
What frequency should I use to tune to concert pitch?
Use 440 Hz, which is A above middle C and the international standard for concert pitch. The A4 preset selects it instantly so you can match your instrument by ear.
Is it safe to listen to test tones on headphones?
Keep the volume low and limit how long you listen, particularly with high frequencies. Start quiet and raise the level only as needed, since sustained pure tones can be tiring and loud tones can be uncomfortable.