A Pure Tone at Any Frequency
440 Hz. That’s concert pitch A. Every orchestra in the world tunes to it. If you need that tone, or any frequency between 20 Hz and 20,000 Hz, this tool generates it right in your browser.
Pick the frequency, pick the waveform, hit play. The Web Audio API synthesizes the sound locally. Nothing gets sent to a server. Nothing gets downloaded.
Four Waveforms
- Sine: a pure, clean tone. No harmonics, no buzz. This is what you want for tuning and testing.
- Square: hollow and buzzy, like an old 8-bit video game. Rich in odd harmonics.
- Sawtooth: bright and aggressive, containing all harmonics. Think of a bowed violin string cranked through a distortion pedal.
- Triangle: softer version of square. Still odd harmonics only, but at lower amplitudes. Sounds a bit like a distant flute.
If those descriptions don’t mean much to you, just click through them while a tone is playing. You’ll hear the difference immediately.
How To
- Set the frequency with the slider or click a quick note button (A4 = 440 Hz, C4 = 261.63 Hz).
- Pick a waveform.
- Adjust volume.
- Click Play Tone. Click Stop when you’re done.
What People Actually Use This For
Tuning instruments by ear. Click the A4 button, get a 440 Hz sine tone, tune your A string to match. Old school, but it works. Some players prefer tuning by ear over a tuner because it trains your sense of pitch.
Testing speakers and headphones. Sweep slowly from 20 Hz up to 20,000 Hz. Listen for dead spots (frequencies that seem quiet or missing), distortion, or physical rattling from your speaker enclosure. A good pair of headphones should reproduce the full range evenly. Your laptop speakers won’t, they typically roll off below 100-200 Hz.
Checking your own hearing. Start at 1,000 Hz and go up. Most adults can’t hear above 15,000-17,000 Hz, and it gets worse with age. This isn’t a medical test, your results depend on your speakers, room noise, and volume, but it gives you a rough idea. See an audiologist for the real thing.
Learning about synthesis. If you’re getting into electronic music production, understanding waveforms is fundamental. Play a sine wave, then switch to square, then sawtooth. Hear how each one sounds different at the same frequency. That’s harmonics at work, the core concept behind every synthesizer.
Tinnitus masking. Some people find that playing an external tone near their tinnitus frequency provides temporary relief. Dial in the frequency with the slider and see if it helps. This isn’t medical advice, talk to an audiologist.
Physics class demos. Frequency, pitch, amplitude, harmonics, the audible spectrum, all of these concepts are easier to teach when students can actually hear them. A tone generator is a standard classroom tool for a reason.
For keeping time during music practice, the Metronome is right here on Toolsvu. To find the BPM of a song, the BPM Detector handles that.
FAQ
What are the waveforms in simple terms? Sine = smooth and pure. Square = buzzy and retro. Sawtooth = bright and harsh. Triangle = mellow and flute-like.
Can I test my hearing with this? Roughly, yes, but it’s not a clinical hearing test. Your results are affected by speaker quality, ambient noise, and volume settings. It’s a fun experiment, not a diagnosis.
Does anything leave my browser? Nothing. The Web Audio API generates sound locally. Zero network traffic.
Why can’t I hear above 16,000 Hz? Age-related hearing loss is completely normal. The hair cells in your inner ear that detect high frequencies are the first to degrade. Most adults over 30 can’t hear much above 16 kHz.
Can I play chords or multiple tones? One tone at a time with this tool. For multi-voice synthesis, you’d need a proper DAW like Ableton or a web-based synth.