Speaker test
Play a tone through the left channel, the right, or both, and confirm each speaker works and is on the side you expect.
Turn your volume down before starting. This test plays a tone through whichever device is selected, and a loud tone through headphones can damage your hearing. The tone starts quietly and only plays while you hold the button.
The tone plays only while the button is held, and starts quietly.
Ready.
Swapped channels are more common than dead ones
If the left tone comes from the right speaker, the cables are crossed or the audio device is configured with the channels reversed. It is easy to miss for months, because most content sounds acceptable either way — until anything relies on stereo positioning.
Nothing here leaves your device
Every one of these tests runs entirely in your browser using standard web APIs. No audio, video, keystroke or controller input is uploaded, recorded on a server, or stored anywhere — there is no upload endpoint for any of it to go to. Closing the tab discards everything.
Common questions
How do I test my speakers?
Play the left channel and confirm the sound comes from the left speaker, then repeat for the right. If both play but from the wrong sides, your channels are swapped.
Why can I only hear one speaker?
Either that channel is muted, the balance control is pushed fully to one side, or a plug is not fully seated — a partly inserted headphone jack very often produces sound in one ear only.