Test your speakers, left and right
Three tones — left only, right only, both — synthesized in this tab. You are the detector: where each tone comes from tells you whether your channels are wired correctly.
Set a comfortable volume BEFORE playing — start low. The tone is a pure 440 Hz sine at a moderate level, but headphone levels depend entirely on your output volume.
- 1. Left only440 Hz · 1.5 s
Sound from the LEFT speaker or earcup only. If it comes from the right, your channels are swapped; from both, the stream is being downmixed.
- 2. Right only440 Hz · 1.5 s
Sound from the RIGHT only — the mirror of step one.
- 3. Both (center)440 Hz · 1.5 s
Equally from both sides, imaging in the middle. One side silent here (after passing its own step) means a dead channel or a loose connection.
- Tones are synthesized in this tab by the Web Audio API — no audio file is downloaded, nothing is recorded, and stopping the test closes the AudioContext entirely.
- This is a listening test: you are the detector. A swapped result on one output (TV via HDMI) and a correct one on another (headphones) is an output-configuration fact, not a browser one.
- Some setups intentionally downmix to mono (accessibility settings, single-speaker devices, some Bluetooth modes) — then every step sounds centered and neither channel is 'broken'.
- This browser does not implement setSinkId, so the test plays through the system default output — switch devices at the OS level if you need to.
Paste, drop, or type to begin. Everything stays on this device.
set a comfortable volume first, then press play