How to Test Earbuds Left and Right Channel (Free Online Test)

The short answer

Open our headphone test with your earbuds in, start at a low volume, and press Left, then Right, then Both. Each button sends a tone to one channel only, with nothing in the other. A good pair puts the left tone in the left ear only, the right tone in the right ear only, and the Both tone in the middle of your head.

The test works with AirPods, Galaxy Buds, Pixel Buds, wired earbuds on a 3.5 mm jack, USB-C earbuds and over-ear headphones, on a phone or a laptop. Nothing is installed and nothing is recorded.

Before you start

• Turn the volume down to about a third. Test tones are steady and can be uncomfortable at full volume.
• Check which bud is which. Most earbuds have a small L and R on the stem or the inside of the housing. Wearing them the wrong way round makes a good pair look swapped.
• Close other apps that might be playing sound, such as a paused video or a call app.
• Charge both buds if they are wireless. A bud on a very low charge can drop out or sound quieter.

Step-by-step: test left, right and both

1. Connect the earbuds and make sure sound is going to them, not to the phone or laptop speaker. Play any song for a second to check.
2. Open the headphone test in Chrome, Safari, Edge or Firefox.
3. Press Left. You should hear a tone in the left ear only. Take the right bud out for a moment: the sound should not change.
4. Press Right. You should hear a different tone in the right ear only.
5. Press Both. The tone should sound centred, roughly in the middle of your head, not pulled to one side.
6. Wiggle the cable if they are wired, near the plug and where it splits, while a tone plays. Crackles or drop-outs point to a broken wire.
7. Repeat on a second device if anything was wrong. This is the step that tells you where the fault is.

What the result means

• Left in left, right in right, Both in the middle: the channels are fine. If music still sounds lopsided, the recording itself may be mixed unevenly; try another song or app.
• Both tones in both ears: Mono Audio is turned on somewhere, so the left and right channels are combined. The earbuds may be fine. See the settings section below.
• Left tone in the right ear: the channels are swapped. Check that you are wearing the buds the right way round. If you are, an adapter, an extension cable or a detachable cable is the usual cause; try without it.
• One side quieter than the other: check the balance slider first, then clean the quiet bud’s mesh. Wax and lint on the speaker grille are a common cause.
• One side silent: on wired earbuds, push the plug fully in and try without any case or adapter. On wireless earbuds, put both back in the case, re-pair them, and test again.
• Sound cuts out when you move the cable: the wire is damaged inside, usually near the plug or the earbud. That doesn’t fix itself.

Check balance and Mono Audio

A slider that has drifted to one side, or Mono Audio left on, causes many “one side is quiet” reports. Menu names vary a little by version and maker, so search Settings for balance or mono if you can’t find them.

• iPhone and iPad: Settings → Accessibility → Audio & Visual. Turn Mono Audio off and drag the Balance slider back to the centre. The slider is sensitive, so check it reads exactly the middle.
• Android: Settings → Accessibility → Audio adjustment (on some versions under Audio or Hearing). Turn off Mono audio and centre Audio balance. Samsung phones also have hearing settings under Accessibility.
• Windows 11: Settings → System → Sound, choose your headphones, and set the Left channel and Right channel sliders to the same level. Mono audio is under Settings → Accessibility → Audio. With many Bluetooth earbuds the two sliders move together; that is normal.
• Mac: System Settings → Sound → Output, choose the headphones and centre the Balance slider.

Also check any equaliser in a music app or the earbuds’ own companion app, and set it to flat while you test. Then run the headphone test again.

Wired and wireless earbuds fail differently

Wired (3.5 mm, USB-C or Lightning)

A plug that isn’t fully in can leave one channel disconnected, and thick phone cases often stop the plug from going all the way in. Take the case off and push firmly. Wipe the metal plug with a dry cloth, and look in the jack with a torch (flashlight) for lint. USB-C and Lightning to 3.5 mm adapters break inside more often than the earbuds do, so try a second adapter if you have one. If the earbuds work on another device, the problem is the jack, port or adapter on the first one.

Wireless (AirPods, Galaxy Buds and others)

Each bud has its own battery, speaker and, on most models, its own connection. If one bud is silent, put both in the case, close the lid for a short while, then try again. If that doesn’t help, remove the earbuds from the phone’s Bluetooth list, reset them using the maker’s steps, and pair them again. Update the earbuds’ firmware in their companion app or settings. If neither bud will pair, our Bluetooth check scans for nearby devices so you can see whether the phone’s Bluetooth radio is working at all.

Clean a quiet earbud safely

Earwax on the speaker mesh makes one side sound muffled or much quieter. Use a dry, soft brush or a dry cotton swab on the mesh, with the bud facing down so debris falls out. Don’t push anything sharp into the mesh, don’t use water, and don’t soak them. A slightly damp lint-free cloth is fine for the outside. If one bud sounds crackly rather than quiet, our muffled or crackling speaker guide covers the same kinds of blockage on phone speakers.

When to repair or replace

• Settings fixed it: nothing to replace. Leave Mono Audio off unless you need it.
• Fails on every device after cleaning and re-pairing: the earbud is faulty. Check the warranty first. Apple, Samsung and most brands can replace a single bud, which usually costs less than a new pair.
• Wired earbuds with a cable fault: cheap pairs are rarely worth repairing; replace them. Earbuds with a detachable cable often only need a new cable.
• Every pair fails on one device: the phone or laptop is at fault. Try a different adapter, then the maker’s support. Our speaker test checks the built-in speakers of the same device.

Buying used earbuds or a used phone? Test both channels before you pay. Fakes and worn pairs often have a weak side. Our guide to testing a used phone covers the rest of the checks, and the microphone side is covered in webcam and mic test.

Spelling note: the UK, Canada and Australia write “centre” and call a flashlight a “torch”. The settings and steps are the same everywhere.