Tone & Frequency Generator
A precise signal generator for testing speakers and headphones, tuning by ear, or finding the limits of your hearing. Pick a waveform, sweep between two frequencies, or add a beat pulse — all generated live in your browser.
Frequency
440.0Hz
Nearest note
A4in tune
Frequency
Waveform & level
Starts low on purpose. High frequencies at full volume can damage speakers and hearing — raise it slowly. Check your system volume too.
Sweep mode
A logarithmic sweep sounds like an even glide because pitch is perceived logarithmically; a linear sweep spends most of its time in the top octave. Playback stops on its own when the sweep finishes.
Beat / pulse mode
Amplitude modulation turns the steady tone into a rhythmic pulse — useful for checking speaker excursion, or for a slow, even beat to practise to.
About this tool
This is a browser-based signal generator built on the Web Audio API. A single oscillator produces the tone, a gain stage controls level, and every change you make is applied as a short ramp rather than a jump, so there are no clicks or pops as you drag. Sweep mode writes the whole frequency ramp onto the audio clock in advance, which keeps it perfectly smooth, and pulse mode adds a second, sub-audible oscillator that modulates the level for a rhythmic beat.
The note readout converts the frequency to scientific pitch notation and shows how many cents off the nearest equal-tempered note it is (A4 = 440 Hz). Start with a low volume and increase it gradually — everything runs locally in your browser and nothing is recorded or uploaded.
- 100% free — no account needed
- Runs in your browser
- Nothing is uploaded
Frequently asked questions
Is Tone Generator really free?
Yes. Tone Generator is completely free on PureBrowser — every feature, with no account, no trial, and no credit card.
Does Tone Generator upload my data?
No. Tone Generator runs entirely inside your browser, so anything you type, paste, or open stays on your own device.
Do I need to sign up or install anything?
Neither. There is no account and nothing to download — open the page and Tone Generator is ready to use on desktop or mobile.
Does Tone Generator work offline?
Once the page has loaded, yes. All of the processing happens locally in your browser, so it keeps working without a connection.
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