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Device tests

Headphone stereo test

The test plays a tone in the left and right channels separately so you can check they aren’t swapped and both play. A 20 Hz – 20 kHz sweep shows which frequencies you hear, and the phase test reveals whether the drivers are wired correctly.

⚠️ Turn the volume down to 20–30% before you start — a test tone is harsher than music. Sound is generated right in your browser; nothing is downloaded or sent.

Turn the volume down to 20–30% before you start.

Put on your headphones, lower the volume and play a tone.

Everything runs in your browser: sound, video and keystrokes are never sent or stored.

What next

How to read the result

  • Left / right — the tone should play in one ear only. In the other ear means swapped channels; silence means a faulty earpiece or cable.
  • 20–20,000 Hz sweep — many headphones and ears don’t reproduce below ~40 Hz or above 15 kHz; that’s normal, especially after 25–30.
  • Phase — the in-phase tone sits “inside your head”, the out-of-phase one spreads out to the sides. If it’s the other way round, one driver has reversed polarity.
  • Balance — the slider moves the tone left and right; centred, the sound should be in the middle.

More tests

Frequently asked questions

Why do I hear sound in only one ear?
A cable broken near the plug, a dirty jack, or system balance or mono audio settings. With TWS earbuds one bud may have disconnected — reset the pair.
Why can’t I hear high frequencies?
The upper hearing limit drops with age: about 17–19 kHz at 20, 13–15 kHz at 40. Headphones also roll off the extremes.
Does this work for speakers?
Yes, left/right and phase checks work the same for a stereo pair. Run the sweep on speakers at low volume.
There’s no sound at all. What now?
Check the system output device and that the tab isn’t muted. On iPhone, turn off silent mode.