This online tone generator plays a pure tone at any frequency you choose. Type a number of hertz or a note such as A4, then press Play. Change the frequency with the slider, the ×½/×2 buttons (one octave down or up) or the arrow keys. Add up to four tones at once, put each on the left, right or both channels, and download the result as a WAV file.
What you can do with it
- Tune an instrument to a reference pitch. ISO 16 sets the standard tuning frequency for A4 at 440 Hz. Choose another reference under A4 = if your ensemble uses one.
- Test speakers and headphones: play low tones to find where the bass fades, and listen for buzzes and rattles at single frequencies. For a guided check use the speaker test or bass test.
- Check left and right: put a tone on one channel only.
- Find the highest tone you can hear on the high frequency sound page.
- Hear beats and intervals: two tones 1–2 Hz apart beat at that rate; tones in a 3:2 ratio make a perfect fifth.
- Science and teaching: show how pitch follows frequency, and how waveforms sound different at the same pitch.
- Make test files: download an exact tone, length and sample rate as a WAV.
Waveforms
| Waveform | Harmonics | Sound |
|---|---|---|
| Sine | None: a single frequency | Pure and soft. Use it for tests and tuning. |
| Square | Odd harmonics (3×, 5×, 7×…), falling as 1/n | Hollow and buzzy, like an old video game. |
| Triangle | Odd harmonics, falling as 1/n² | Between sine and square, slightly flute-like. |
| Sawtooth | All harmonics, falling as 1/n | Bright and brassy. |
The browser generates band-limited versions of these waveforms, so they do not alias. A square or sawtooth tone sounds louder than a sine at the same level setting because of its harmonics.
Frequency and notes
The generator names the nearest note for every frequency, in equal temperament with A4 as the reference. Each semitone is the twelfth root of two (about 5.9%) above the last, and each octave doubles the frequency. For example, middle C (C4) is 261.63 Hz and A5 is 880 Hz at A4 = 440 Hz. See the full table on the pitch detector page.
How high and how low can it go?
The lowest setting is 1 Hz. The highest is half your device's sample rate, the Nyquist limit: 22,050 Hz at 44.1 kHz or 24,000 Hz at 48 kHz. We stop just below that. A browser cannot make 30,000 Hz or 40,000 Hz; any site that says otherwise is producing something else. In practice your speakers or headphones usually fade out well before the limit, and very low tones need a subwoofer to be heard at all.
Safety
Pure tones can be uncomfortable or harmful at high levels, especially high frequencies, and can damage small speakers. Start with your device volume low and turn it up slowly. Every tone fades in and out to avoid clicks, and our output is limited to −3 dBFS. That protects against clipping, but not against a loud amplifier setting. Hearing limits for everyday noise are on the decibel chart.
WAV downloads and links
Download WAV renders exactly what is set up, at 44.1 or 48 kHz, 16-bit stereo, at the level shown for each tone in dBFS (not your listening volume). If several tones would add up past full scale, they are scaled down together so the file does not clip. Copy link puts every setting in the address, so the link reopens the same tones.
Need a sweep instead? Switch to Sweep above or open the frequency sweep generator. For phone keypad tones, use the DTMF tone generator.
Common questions
How do I play a specific frequency?
Type it in hertz (for example 440 or 1.5k) or as a note such as A4, then press Play. You can also open a link like /tone-generator/?f=440.
What frequency is A4?
440 Hz. ISO 16 sets 440 Hz as the standard tuning frequency for the A in the treble stave. Some orchestras tune slightly higher, so the generator lets you change the reference.
Can I play two tones at once?
Yes. Press Add a tone for up to four tones, each with its own frequency, waveform, level and channel.
Why can't I hear very high or very low tones?
Your speakers or headphones may not reproduce them, the volume may be too low, or the tone is beyond what your ears can hear. Try headphones, and raise the volume slowly.
Can it play 30,000 Hz?
No. A browser can only produce frequencies up to half its sample rate, about 22,050 Hz at 44.1 kHz or 24,000 Hz at 48 kHz, and most speakers stop well below that.
Is it safe for my speakers?
At moderate volume, yes. High levels of high frequencies can damage tweeters and small speakers, and loud tones can harm hearing. Start quietly.
Last reviewed 14 November 2026 by Sri Murugan Systems. Found a mistake? Tell us.