Headphone Test
Play a tone in each ear to check both sides of your headphones or earbuds.
Audio Balance Test
Move a steady tone between your left and right channels to hear whether one side of your speakers, headphones or earbuds is louder than the other. You judge the center by ear; nothing is measured.
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 check left and right balance
- Set the volume low, sit midway between your speakers or put your headphones on the correct ears, and press Play.
- Press Center and listen. With speakers the tone should sound straight ahead; with headphones, in the middle of your head.
- If it leans to one side, drag the Balance slider until the tone sounds centered, then read the value. Centered at 12% right, for example, means the right side is quieter or a setting favors the left.
- Press Alternate to hear full left and full right in turn, 1 second each, and compare how loud they are.
- Press Sweep to glide the tone from left to right and back every 6 seconds, starting from the slider's position. Moving the slider or pressing Center takes over without stopping the tone.
- Press Stop when you are done.
What is audio balance?
Audio balance is how loud the left channel plays compared with the right. When it is even, a sound sent equally to both sides seems to come from the center. When it is off, the sound leans toward the louder side, whether the cause is a balance setting, a blocked or loose earpiece, or where you sit.
Where to change the balance setting
| Device | Where to find balance |
|---|---|
| Windows 11 | Settings > System > Sound, select your output device, then set the Left channel and Right channel sliders to the same value. |
| Mac | System Settings > Sound, select your device under Output, then center the Balance slider. |
| iPhone and iPad | Settings > Accessibility > Audio & Visual > Balance. |
| Android | Accessibility settings, often under Audio or Hearing enhancements. The menu name varies by manufacturer. |
| Headphone apps | Some earbud and headphone companion apps have their own balance or per-ear sound settings. Check them too. |
What to do when one earbud or speaker is quieter
A side that is completely silent needs a different check: start with the Headphone Test or the Speaker Test, then see one earbud not working. For a side that is only quieter, work through these steps in order.
- Check the balance setting, using the table above.
- Clean the earbud mesh and ear tips gently with a soft, dry brush or cloth. Earwax and dust can muffle one side.
- Reseat the earbud or try another ear tip size. A loose seal loses volume and bass.
- For wireless earbuds, put both in the case, take them out and reconnect. If one side stays quiet, reset them following the maker's instructions.
- With speakers, sit the same distance from both and move anything that blocks one of them.
- Wear the headphones the other way round, or try another pair, and press Alternate. If the quieter side moves to your other ear or goes away, the headphones are at fault. If the same ear stays quieter every time, the difference may be in your ear, and an audiologist or a doctor can check it.
What this test can detect
- A tone at Center that leans toward one side.
- The Balance position where the tone sounds centered, a rough sign of which side is quieter.
- A side that sounds quieter when Alternate switches between them.
- Swapped channels or headphones on the wrong ears: the meter shows left while you hear right.
- A jump or dropout as Sweep moves the tone across.
How it works
The page plays a steady 440 Hz sine tone from the Web Audio API through a stereo panner. The Balance slider has 201 steps, from full left through Center to full right, and the meter marks the same position. Sweep follows a smooth 6-second cycle; Alternate holds each side for 1 second, starting on the left.
The pan is equal-power: at Center each channel gets about 71% of the signal (−3 dB), and at full left or right one channel gets all of it. So a reading such as 12% right is a position, not a 12% difference in loudness. Volume starts at 40%; at the top of the Volume slider, a tone fully on one side peaks at about −6 dBFS.
Limitations
- You judge the center by ear. Small differences between your two ears move it, so two people can hear the center in slightly different places.
- The page cannot change your balance. Adjust it in the settings listed above.
- The single 440 Hz tone can miss an imbalance that shows only in the bass or treble. To compare the sides at other pitches, use Left and Right in the Tone Generator.
- Stereo only; the Surround Sound Test checks each channel of a 5.1 or 7.1 system. Playback stops when the tab is hidden, for example when you switch tabs.
Frequently asked questions
Does the percentage measure how much quieter one side is?
No. It is a pan position you choose by ear, not a loudness measurement. It shows which side is weaker and gives you a reference to compare after you change a setting or clean an earbud.
Why does the tone move when I turn my head?
Because a steady tone reflects off the walls and forms louder and quieter spots in the room, so small head movements change what each ear hears. Keep your head still and sit midway between the speakers. Headphones avoid the room; if the tone moves as you turn with headphones on, head-tracked spatial audio is on.
Why does one side sound louder only in some songs?
Because many recordings place voices and instruments off center on purpose, so music is a poor reference for balance. A centered test tone has no such bias: if Center sounds centered here, the channels are even at that pitch.
Is balance the same as mono audio?
No. Balance sets how loud each side is. Mono audio, found in the Accessibility settings, mixes both channels so each side plays the same sound. With Mono audio on, the tone stays centered wherever you move the slider.