Decibelwerk
Home › Free tools

Online tone generator

A clean test tone from 20 Hz to 20 kHz, made in your browser. Start with the volume low.

Generate a tone

OSC · SINE · A4
440.0Hz

Your device's speakers set the real limits: small speakers barely play below 100 Hz, and many stop well before 20 kHz.

What to use it for

  • Speaker and headphone tests. Sweep the frequency slowly. Rattles, buzzing or a sudden drop in volume point to a damaged driver or a loose panel.
  • Your hearing range. Put on headphones, set a comfortable level at 1 kHz, then raise the frequency until you can't hear it. It's a rough check, not a hearing test.
  • Tuning reference. A4 is 440 Hz, the standard concert pitch.
  • Room problems. Low tones between 40 and 120 Hz show where a room booms or goes dead. Walk around while one plays.

Sine, square, sawtooth, triangle

WaveSoundGood for
SinePure, one frequency onlyHearing range, tuning, finding resonances
SquareHollow and buzzy, odd harmonicsHearing whether a speaker distorts
SawtoothBright and harsh, every harmonicTesting the full treble range at once
TriangleSoft, a little brighter than sineGentle reference tones

Then measure what came out

A tone generator tells you what you sent; a meter tells you what arrived. Play a 1 kHz tone and measure it at your listening position to set a level, or compare left and right speakers. See how to measure decibels on iPhone.

Frequently asked questions

What is the highest frequency I should be able to hear?

Young adults with healthy hearing usually hear up to around 17–20 kHz. The top of the range drops with age and noise exposure, so many adults stop hearing somewhere between 12 and 16 kHz. Laptop and phone speakers also roll off at the top, so try headphones before drawing conclusions.

Is it safe to play tones?

At a sensible volume, yes. Start with the level low and the device volume low, especially on headphones, and turn up slowly. Very high tones can be uncomfortable even when they seem quiet.

Can a tone get water out of my phone speaker?

A low tone around 165 Hz can shake loose drops sitting on the speaker grille, which is why the Decibelwerk app has a pulsed speaker cleaner. Apple's own advice for a wet iPhone is to tap it gently with the connector facing down and let it dry in moving air.