Headphone Test
Check that left is left and right is right, sweep sound across your head, find a balance offset, test driver polarity and take a quick which-ear quiz. Works with headphones, earbuds and headsets, right in your browser.
Start quiet. Put the headphones on, press a button, then raise the volume slowly until the sound is clear but comfortable. Never test at full volume.
1. Left and right channel test
Left should only be heard in your left ear, right only in your right, and centre should sit in the middle of your head. Pink noise is easier to place than a pure tone.
2. Stereo sweep
The noise starts on the left, glides to the right and comes back. It should move smoothly with the dot. A jump, a gap in the middle or movement in the wrong direction points to a wiring or channel problem.
3. Balance check
Centred: both sides sound equally loud to you.
4. Polarity (phase) test
Both samples are the same noise. In one of them we flip the right channel upside down. Listen to both and pick the one that sounds fuller, with more bass, and focused in the centre of your head.
5. Which ear? quiz
5 sounds play in a random ear. Say which ear you heard each one in. It catches swapped channels that are easy to miss.
How to read this headphone test
Wearing them the right way round
Look for a small L and R printed inside the headband, on the stem of each earbud or on the cable. Many headsets also mark the left side with a raised dot or put the microphone boom on the left. If the left and right test and the quiz both come out reversed while the markings say you are wearing them correctly, the swap is in the cable, adapter or the headphones themselves.
One side quieter than the other
The most common cause is earwax or dust in the mesh. Clean it gently with a dry soft brush. Then check the system balance slider and Mono Audio switch: on iPhone under Accessibility, Audio and Visual; on Android under Accessibility, Audio adjustment; on Windows under Accessibility, Audio; on a Mac under Accessibility, Audio. For wireless earbuds, unpair, reset and pair again, since one bud can lose sync.
A balance offset under 3 dB is normal, since few people hear identically in both ears. If the same side is weak on every pair you try, it may be your hearing; the hearing test can help.
Polarity and the knock-off problem
When one driver is wired backwards, it pushes air while the other pulls. Bass cancels out and voices feel diffuse, as if they sit inside your skull. Branded headphones rarely ship like this, but cheap copies of well-known earbuds sometimes do, along with swapped channels. If a "premium" pair fails the polarity test or the quiz, that is a strong hint it is not what the box claims. Use the frequency response test to check how much bass and treble they really reach.
Bluetooth delay and mono speakers
Bluetooth adds roughly 100 to 300 ms between pressing a button and hearing the sound, and the browser usually cannot measure all of it. That lag is normal and does not affect these results. If you are testing without headphones, note that most phone speakers and many laptop speakers are mono or almost mono, so left and right sound the same and the polarity samples may nearly vanish.
Related tools
Check speakers with the sound test, measure what your gear can reproduce with the frequency response test, find out if you can hear the difference between file qualities with the audio blind test, and check your own ears with the hearing test.
Frequently asked questions
What is the difference between Left, Right, and Center?
The Left button plays the left channel only, and Right plays the right channel only. Center plays both channels together at equal power so the sound sits in the middle and is not louder than one side. The quiz uses the same split: the sound is either the left channel or the right channel, and the score says played L or played R. Left ear and Right ear only record your answer. If Left is loud in your right ear, the channels are swapped or the headphones are on backwards.
What does the polarity test flip?
Sample A and sample B are pink noise. One of them, chosen at random each round, flips the right channel upside down with a negative gain. The other keeps both channels in phase. Listen for the sample that sounds fuller, with more bass, and focused in the centre. After you pick, the result says whether you chose the in-phase sample or the flipped one. Play A then B is a single playback with a short gap, and the right channel flips during that gap.
Why is there silence when I press a button?
A message under the volume slider means playback never started. "No sound: the browser blocked audio" means the browser refused to resume the audio context. The context is created and resumed from your click, and playback does not start if that fails. Click the same control again and allow this site to play sound. If the message says this browser does not support Web Audio, the test cannot play here. Quiz rounds after the first start on a short timer. If one of those stays silent and the blocked-audio message shows, press Replay so the browser gets a new click.
Do speakers work the same as headphones?
Headphones, earbuds, and headsets send the left and right channels to different ears. Many phone and laptop speakers are mono, so Left and Right sound the same. After an audio context exists, the page shows how many output channels the browser reports, and one channel means both ears hear the same thing. On a mono mix the flipped polarity sample can cancel and almost vanish, so the two samples can sound the same. Bluetooth can add delay the browser does not report. That delay does not change which channel plays.
What do the sweep and the balance slider show?
The sweep is six seconds of pink noise that starts on the left, moves to the right, and comes back with the dot. Balance plays pink noise until you press Stop. Move the slider to the Quieter left or Quieter right side until the noise sits in the middle. The readout is how many decibels that side was turned down, from 0 to 12 in steps of 0.5. The number is the offset you set. It is not a hearing measurement.
How loud is it, and which sound plays?
The volume slider starts at 25 percent unless this browser saved a different level. Master gain is the square of volume divided by 100, so 25 percent stays quiet and 0 is silent. Raise it only until the sound is clear. Left, Right, Center, and the quiz use pink-noise bursts or a 500 Hz tone, whichever you select. The sweep, the balance noise, and both polarity samples always use pink noise. Stop, starting another sound, or leaving the page stops the tone or the noise.