I hear the left tone from the right side — what does that mean?

Your channels are swapped, usually because of a reversed cable, a wrong connector, or a balance setting. Headphones can also simply be worn the wrong way round. If the swap persists across devices, the audio cable or adapter is the likely cause.

Why can I not hear the very low or very high tones?

Small laptop and phone speakers cannot reproduce deep bass or the highest treble, so missing tones at the extremes are normal for them. On full-size speakers or good headphones you should hear the whole sweep; a gap in the middle, or a buzz, points to a damaged driver.

Is it safe to run the tones at high volume?

Start at a low volume and raise it gradually. Test tones are continuous and can be louder than they feel, which is hard on both your ears and small speakers. You do not need high volume to tell whether a channel works.

Is my camera, microphone or data sent anywhere?

No. Every test runs locally in your browser on your own device. When a test needs your camera or microphone, the feed is shown to you and nothing else: it is never uploaded, never recorded to a server, and never stored. Close the tab and it is gone. You can confirm it by disconnecting from the internet after the page loads; the tests still work.

Speaker Test

Check your speakers or headphones play correctly. Send a test tone to the left channel, the right channel or both, so you can confirm each side works and is wired the right way round. Run a slow frequency sweep to hear whether every part of the range comes through. Free and instant.

No app to install
100% free
Nothing is recorded
No sign-up, no email
Works on any device

Read the guide: How to Test Your Speakers

440 Hz test tone

Pick a channel

Frequency sweep

Plays low to high over six seconds. You should hear it rise smoothly with no gaps or buzzing.

How to use it

1
Put on or turn up your audio

Make sure the device you want to test is selected in your system and the volume is at a comfortable level.
2
Test each channel

Play the left-only and right-only tones in turn. You should hear sound from just that side, which confirms the wiring and balance.
3
Run the sweep

Play the frequency sweep to hear low to high tones. A gap or buzz points to a damaged driver or a balance problem.

When it comes in handy

New headphones or speakers

Confirm both sides work and are not swapped before you rely on them for music or calls.

Surround and balance checks

Verify left and right are correct and balanced, which matters for stereo mixing, gaming and films.

Diagnosing a dead side

Pin down whether silence on one side is the speaker, the cable or a balance setting turned all the way over.

Instant & 100% private — nothing is recorded

The test runs right here in your browser. When it needs your camera or microphone, the feed is shown to you and nothing else: never uploaded, never recorded to a server, never stored. There is no sign-up and no email wall, and most tests keep working with no connection at all.

Frequently asked questions

I hear the left tone from the right side — what does that mean?: Your channels are swapped, usually because of a reversed cable, a wrong connector, or a balance setting. Headphones can also simply be worn the wrong way round. If the swap persists across devices, the audio cable or adapter is the likely cause.
Why can I not hear the very low or very high tones?: Small laptop and phone speakers cannot reproduce deep bass or the highest treble, so missing tones at the extremes are normal for them. On full-size speakers or good headphones you should hear the whole sweep; a gap in the middle, or a buzz, points to a damaged driver.
Is it safe to run the tones at high volume?: Start at a low volume and raise it gradually. Test tones are continuous and can be louder than they feel, which is hard on both your ears and small speakers. You do not need high volume to tell whether a channel works.
Is my camera, microphone or data sent anywhere?: No. Every test runs locally in your browser on your own device. When a test needs your camera or microphone, the feed is shown to you and nothing else: it is never uploaded, never recorded to a server, and never stored. Close the tab and it is gone. You can confirm it by disconnecting from the internet after the page loads; the tests still work.