Online Tool Store
Tone Generator
Generate a steady sine, square, sawtooth, or triangle wave at any frequency from 20 Hz to 20 kHz, right in your browser — useful for audio testing, tuning, and hearing checks.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Frequency
Ready — press Play to start the tone.
Start at a low volume — a pure tone can be uncomfortably loud, especially at high or low frequencies or through headphones.
Space also starts or stops the tone.
How it works
- Set a frequency — type it directly, drag the slider, or click a preset.
- Choose a waveform and starting volume, then click Play.
- Adjust frequency, waveform, or volume freely while it's playing — the tone updates live.
How the frequency slider is mapped
The slider position maps exponentially across the 20 Hz-20,000 Hz audible range, not linearly, so it matches how pitch is actually perceived:
frequency = 20 × (20,000 / 20)^(slider position / slider max)
The number field next to it is exact and linear — type a precise value like 440 Hz directly if you know what you want, and use the slider when you're sweeping by ear instead.
FAQ
What is a tone generator actually used for?
Common uses include testing speakers or headphones for dead channels or frequency response, tuning instruments (440 Hz is the standard A4 concert pitch), checking room acoustics or rattles at specific frequencies, and rough hearing-range checks — most adults stop hearing well somewhere past 15-17 kHz.
What's the difference between the waveforms?
Sine is a pure single frequency with no overtones — the cleanest, most neutral test tone. Square, sawtooth, and triangle waves all contain the same fundamental frequency plus a stack of harmonic overtones, which is why they sound noticeably 'buzzier' or brighter than a sine wave at the same frequency, and are more typical of synthesizer and testing waveforms than of anything found in nature.
Why is the frequency slider not evenly spaced?
Pitch perception is logarithmic, not linear — the jump from 100 Hz to 200 Hz sounds like the same-size step as 1,000 Hz to 2,000 Hz, even though the second jump is 10x bigger in Hz. The slider is mapped the same way, so equal slider movement feels like an equal pitch change across the whole range, instead of the low end being crammed into the first few pixels.
Can changing the frequency or waveform hurt my speakers?
Sustained tones at very high volume — especially at very low frequencies through small speakers — can stress speaker components more than typical music does. Keep the volume moderate, particularly at the extreme ends of the range, and stop immediately if anything sounds distorted or strained.
Is anything about my session sent anywhere?
No. The tone is synthesized locally with the Web Audio API's built-in oscillator — nothing is uploaded, recorded, or logged.
How we compare
| Feature | Online Tool Store | Dedicated signal-generator apps | Other online tone generators |
|---|---|---|---|
| No install required | ✓ | ✗ | ✓ |
| Adjust frequency and waveform live while playing | ✓ | ✓ | Varies — some require stopping first |
| Free, no ads, no daily limit | ✓ | Often a paid app | Varies — many are ad-heavy |
If you just need a quick, precise test tone — not a full audio-engineering app — Tone Generator gets you there in one page, with live adjustment while it plays.