Speaker Test
Test left and right audio channels to make sure your speakers work.
Not playing
Key features
Play a tone through your left channel, right channel, or both at once to confirm your speakers or headphones are wired correctly and both sides actually work. Handy for checking new headphones, tracking down a “quiet” side, or confirming a speaker setup after moving cables around.
The tone is generated locally in your browser using the Web Audio API — nothing is uploaded, downloaded, or played without you pressing a button first.
How to use
Set a safe volume
Start with your device volume low, especially if you’re wearing headphones.
Play a channel
Press "Left", "Right", or "Both" to play a test tone through that channel.
Confirm what you hear
You should hear the tone only from the side(s) you selected — anything else points to a wiring or balance issue.
Frequently asked questions
I pressed "Left" but I hear sound from both sides — what does that mean?
That usually means your audio output is set to mono somewhere in your OS or app settings, or you’re listening through a single speaker/soundbar rather than a true stereo pair. Check your system sound settings for a "mono audio" toggle.
I don't hear anything at all — what should I check?
First check your device volume and that the correct output device (speakers/headphones) is selected in your system sound settings. Also make sure this browser tab isn't muted — some browsers show a mute icon on the tab itself.
What frequency is the test tone?
It’s a 440 Hz sine wave — the same reference pitch (concert A) used to tune instruments — chosen because it’s clearly audible on virtually any speaker or headphone.
Is the audio recorded or sent anywhere?
No. The tone is synthesized locally using the Web Audio API and played directly to your output device — nothing is uploaded or transmitted.