How to Use an Online Tone Generator

A tone generator produces a single, steady frequency — a pure tone — at a pitch you choose. Unlike music, which blends many frequencies, a pure tone is one clean sine wave, which makes it perfect for tuning, testing, and measurement.

An online generator does this with your browser's Web Audio API, so there's nothing to install. You set a frequency in hertz, pick a waveform, and the tone plays through your speakers or headphones instantly.

For tuning, the reference is A4 at 440 Hz, the note most instruments tune to. Play 440 Hz and match your instrument's A against it, or type another frequency if your ensemble tunes higher, such as 442 Hz.

For audio testing, sweep or step through frequencies to hear where speakers or headphones distort, rattle, or drop out. For a hearing check, slowly raise the frequency and note where the tone disappears — most adults stop hearing somewhere between 15 and 17 kHz, and the ceiling lowers with age.

The tool keeps every control on one screen so you can adjust the tone while it plays.

A pure tone puts all its energy at one pitch, so it can sound piercing and feel loud even at modest volume, especially at high frequencies. Always begin quiet and increase slowly.

High-volume low-frequency tones can also stress speakers, particularly small ones, so keep sub-bass tones gentle. Short bursts are safer than long sustained playback when you're testing at the edges of the range.