Audio Balance Test
Move a tone between left and right to hear whether one side is louder.
Headphone Test
Play a tone in your left ear, your right ear or both to check that each side of your headphones or earbuds works and that you are wearing them on the correct ears.
Lower your volume before starting, especially with headphones. Nothing plays until you press a button.
Stopped
Runs entirely in your browser. Test results, audio and video never leave your device.
How to test headphones left and right
- Set the volume low and put the headphones on, with L on your left ear and R on your right.
- Press Left, then Right. Each tone should play in one ear only, and the matching L or R lights up.
- Press Both. The tone should sound centered, in the middle of your head.
- Press Separation. The tone swaps ears every 1.5 seconds, and the page shows which ear should be silent.
- While Left or Right plays, gently move the plug and the cable near it. Crackles or dropouts point to a worn cable, plug or socket.
- To stop the tone, press the highlighted button again or press Stop.
How do you tell which earbud is left and right?
Look for the L and R marks, then confirm by ear: a tone sent to the left channel should play only in the earpiece on your left ear. The marks are usually on the earbud stem or inner shell, or inside the headband or earcup. If the Left tone plays in your right ear, you are most likely wearing them on the wrong ears.
Why you hear the left tone in both ears
At full left the page sends nothing to the right channel, so a tone in the wrong ear comes from a setting, the connection or the volume. If one side stays silent, see one earbud not working.
| Cause | What to do |
|---|---|
| Mono audio is on | Turn it off. Windows 11: Settings > Accessibility > Audio > Mono audio. Mac: System Settings > Accessibility > Audio > Play stereo audio as mono. iPhone: Settings > Accessibility > Audio & Visual > Mono Audio. Android: search Settings for Mono audio. |
| Spatial audio or virtual surround is on | Turn off spatial audio and head tracking, Windows Sonic or Dolby Atmos for Headphones, or the surround effect in your headset software, then test again. |
| A Bluetooth headset is in call mode | Many Bluetooth headsets switch to a mono hands-free mode while an app or tab uses their microphone. Close those apps and tabs, then test again. If the headset appears twice in your sound settings, choose the stereo output, not the hands-free one. |
| The plug is not fully in, or the cable is damaged | Push the plug all the way in; a thick phone case can stop it. A damaged plug or cable can leak one side into the other, so try another cable or pair. |
| The volume is high | A faint tone in the other ear is normal at high volume, because sound leaks through the air and through your head. Lower the volume and listen again. |
What this test can detect
- An earpiece that stays silent, or is much quieter, when its side plays.
- Headphones on the wrong ears: the Left tone plays in your right ear.
- Sound in the ear that should stay silent during Left, Right or Separation, often a sign of mono audio, spatial audio or Bluetooth call mode.
- A plug or cable fault that crackles or cuts out when you move it.
How it works
The page plays a continuous 440 Hz sine tone, generated with the Web Audio API and panned fully left, fully right or to the center. Each tone starts silent and fades in over 15 ms once the panner has had 40 ms to reach its side. A change of side fades the tone out, moves it while silent and brings it back about 80 ms later, so the switch does not spill into the other ear. Nothing is recorded or measured.
Separation alternates left and right every 1.5 seconds and never plays both. Volume starts at 40%. At the top of the Volume slider, a tone in one ear peaks at half of digital full scale, about −6 dBFS.
Limitations
- This is a listening check. It cannot measure channel separation, crosstalk or frequency response.
- The single 440 Hz tone cannot show problems that appear only in the bass or treble. For crackling or buzzing, use the Audio Distortion Test.
- Bluetooth adds a short delay, and some earbuds take a moment to wake, so the start of a tone can be cut off. When Bluetooth headphones lag behind video, the Audio Latency Test estimates the delay.
- Bone-conduction headphones reach both ears through the skull, so some sound on the silent side is expected.
- Playback stops when the tab is hidden, for example when you switch tabs or minimize the window.
Frequently asked questions
Can I test my headset microphone here?
No, this page only plays sound. Use the Microphone Test to check that the headset mic picks up your voice, then press Stop there before testing sound here: an open mic can put a Bluetooth headset into mono call mode.
Why does sound come from only one earbud?
Often it is the connection or a setting rather than the earbud itself. For wired headphones, push the plug fully in and move the cable while Left or Right plays. For wireless earbuds, charge both, put them back in the case and reconnect. Also check that the balance is centered. If the same side stays silent on another device, that earbud or its cable is faulty.
What if one earbud is quieter than the other?
Compare the two sides on the Audio Balance Test. It lets you find where a tone sounds centered and lists the usual causes and fixes, from a blocked mesh or loose ear tip to a balance setting that is off center.
Does this work with Bluetooth earbuds?
Yes. The page plays through your device's default output, whether wired, USB or Bluetooth. Select the earbuds as the output in your sound settings first; the page cannot choose a device itself.
Does this test AirPods fit or noise cancelling?
No. It checks that each ear plays the correct channel. AirPods Pro have an Ear Tip Fit Test in the AirPods settings on an iPhone, and other earbuds may offer a fit check in their companion app.