How to use the Tone Generator
- Type a frequency or drag the slider (it’s logarithmic, like hearing).
- Pick a waveform and press Play; step by semitones or octaves.
- Use a preset, or the sweep to hear the full range.
Hearing range
Young people hear roughly 20 Hz to 20 kHz; the upper limit drops with age, often to 14–16 kHz by middle age. Laptop and phone speakers rarely reproduce much below 100 Hz, so a low tone you can’t hear may simply not be played.
Waveforms
A sine wave is a pure tone. Square, sawtooth and triangle waves add harmonics, which sound brighter and buzzier at the same frequency.
Also searched as: frequency generator, online tone generator, sine wave generator, hz generator, 440 hz tone, test tone.
Tools that pair well with the Tone Generator
- Speaker Test — Check that your speakers or headphones work and are wired the right way round: play a tone or voice in the left, right or both channels, then test bass and phase.
- Metronome — A precise online metronome for practice: set the BPM or tap the tempo, choose the time signature, and hear an accent on beat one — with a visual pulse too.
- Mic Test — Check that your microphone works and sounds right before a call, stream or recording — see the live level, watch the waveform and play back a short test recording.
- Voice Recorder — Record your voice or any sound from your microphone right in the browser.
Frequently asked questions
What frequency is A4?
440 Hz is the standard tuning pitch for A above middle C.
Can a tone damage my speakers?
Very loud, sustained low or high tones can. Keep the volume moderate, especially with sweeps.
Is anything uploaded or recorded?
No. Everything runs in your browser; results and settings are kept on this device only.
Can I install Tone Generator as a web app and use it offline?
Yes. Tone Generator is an installable web app (PWA) — installed from your browser, not downloaded from an app store. Click Install app at the top of this page in Chrome or Edge (Windows, macOS, Linux, ChromeOS) or on Android, use Share → Add to Home Screen on iPhone and iPad, or File → Add to Dock in Safari 17+ on a Mac. It then opens in its own window with its own icon, and because it runs entirely in your browser it keeps working offline. Firefox on desktop can’t install web apps. How installing works.