Left / Right Speaker Test — Check Stereo Channels
Test your speakers online: left / right channel tones, a 20–200 Hz bass sweep and pink noise — all generated in your browser.
Processed entirely in your browser — nothing you enter here is ever uploaded.
Result
About this tool
This page opens the speaker test focused on the left / right check: press Left and the tone must come from your left speaker only, press Right and it must move to the right one, press Both and it should sit in the center.
A left / right test catches the two most common stereo faults in seconds: channels wired the wrong way around (everything sounds mirrored) and one channel that is silent because of a broken cable, plug or driver. If the tone plays on the wrong side, swap the speaker cables or the balance setting — not your ears.
The tone is generated live by the Web Audio API and steered with a stereo panner, so nothing is downloaded and nothing leaves your browser. When both channels pass, try the bass sweep and pink noise on the full speaker test page.
Example. The left-channel control plays the selected tone through a stereo panner hard left, and the bass control sweeps from 20 Hz to 200 Hz over 8 seconds.
Limit. The tone frequency is clamped between 100 Hz and 2000 Hz, and the sweep never goes above 200 Hz.