Ready ⚠ Start at low volume: test tones can damage hearing and speakers.
Tone Generator

Online Tone Generator

1000
Hz
Click the large frequency display to type a value. Audio is generated locally by Web Audio.
20Hz 20kHz
1000 Hz
B5 +9¢
sine
Center
−14 dB
Ready. Press Play for a steady tone, or Sweep for a 20 Hz → 20 kHz test.

Stereo A/B test

About the Online Tone Generator

Generate precise test tones directly in your browser: choose sine, square, triangle or sawtooth waveforms, set any frequency, and use sweeps to test speakers, subwoofers, headphones and stereo channels. Audio is synthesized locally with the Web Audio API — no uploaded audio files.

How do I test my left and right speakers?

Play a mid-range tone (for example 440 Hz) and use the channel/balance control to route it to one side at a time. If sound comes from the wrong side, the speakers or the plug are swapped; if one side is silent, check the cable and balance settings before blaming the speaker.

How do I test a subwoofer?

Sweep or step through the 20–80 Hz range at moderate volume. A working subwoofer reproduces these frequencies clearly; rattling or buzzing at specific frequencies reveals loose parts or room resonances. Small desktop speakers producing nothing below 60–80 Hz is normal.

What frequency range can humans hear?

Roughly 20 Hz to 20 kHz for young, healthy ears. The upper limit naturally drops with age — losing everything above 15–16 kHz as an adult is common. When exploring your own range, always start at low volume: high frequencies can be loud without feeling loud.

What is the difference between sine, square, triangle and sawtooth waves?

A sine wave is a single pure frequency and is the standard for testing. Square, triangle and sawtooth waves add harmonics above the base frequency, which makes them sound harsher and makes them useful for hearing distortion, rattle and resonance problems that a sine tone can hide.

Is it safe to play test tones at full volume?

Start low, always. Sustained pure tones concentrate all their energy at one frequency and can damage both hearing and small speakers faster than music at the same perceived loudness. Increase the level gradually and stop at the first sign of distortion.

Help — Tone Generator

Play starts a steady oscillator at the selected frequency. Click the large frequency number to enter an exact value from 20 to 20000 Hz. The Note card shows the nearest equal-tempered note (e.g. A4) plus cents deviation.

Keyboard shortcuts: P/Space play/stop · S sweep · R reset · M mute · A A/B test · 1–6 waveform · F fullscreen · H toggle side controls · V view (waveform/spectrum) · ? help · Esc stop / close dialog (in the frequency box, Esc cancels the edit).

Privacy: audio is generated locally with the Web Audio API; nothing is uploaded, and the page's Content-Security-Policy blocks all network connections. localStorage keys under the tonetest: prefix: memory (M1–M5 frequencies), wave (last waveform), visualMode (waveform/spectrum) and controlsVisible. Volume, balance, frequency, sweep settings and phase invert are not saved. The light/dark theme is shared by all BeogradPC tests under bpc:theme. Export saves a JSON file to your device only; it contains your browser user agent, platform and language, screen size, colour depth and pixel ratio, viewport size, the current generator settings and the audio output's sample rate and latency.