Audio · left right test
Left Right Audio Test: Is Your Stereo Correct?
This left right audio test plays a beep in your left channel, then your right, and asks where you heard each one. In ten seconds it tells you whether your stereo is correct, swapped, playing in mono, or silent on one side — and how to fix it. Use it for headphones, earbuds, speakers and game headsets. It starts at a safe volume and runs in your browser.
How the left right audio test works
- Step 1
Lower the volume
Turn your system volume down and wear headphones the right way round (look for the L and R marks).
- Step 2
Play left, then right
Each button plays three beeps on one channel only. Choose where you heard them.
- Step 3
Get the verdict
Correct, swapped, mono or one side silent — with the setting or cable to check.
What each result means
| Result | What happened | Fix |
|---|---|---|
| Left and right are correct | Each channel played only from its own side. | Nothing to fix. |
| Left and right are swapped | Sound meant for the left came out on the right, and vice versa. | Check you're wearing headphones the right way round (look for L/R marks). For speakers, swap the cables. Also check Windows/macOS sound settings for a swap or balance option. |
| Left channel is silent | Nothing (or the wrong side) played when only the left channel was sent. | Check the balance slider in your system sound settings, reseat the plug or cable, and try another device. If one earbud or speaker stays silent everywhere, it's likely a hardware fault. |
| Right channel is silent | Nothing (or the wrong side) played when only the right channel was sent. | Check the balance slider in your system sound settings, reseat the plug or cable, and try another device. If one earbud or speaker stays silent everywhere, it's likely a hardware fault. |
| Playing in mono | Both channels came out of both sides, so stereo separation is lost. | Turn off 'Mono audio' in accessibility settings (Windows: Settings › Accessibility › Audio; macOS: System Settings › Accessibility › Audio; iOS/Android have the same switch). Bluetooth headsets in hands-free/call mode are also mono. |
| No sound at all | Neither channel was heard. | Unmute and raise the volume, check the correct output device is selected, and make sure the browser tab isn't muted. |
What this test can and can't tell you
Reliable: Definitive channel check. Sound sent to one channel only can't come out of the other side unless something is swapped or mixed to mono.
Estimate: Spatial audio can blur it. Spatial or virtual-surround processing (Dolby Atmos for headphones, Windows Sonic, AirPods spatial audio) can spread a one-sided beep. Turn it off for the test.
Limit: Not a hearing test. If you hear one side quieter on every pair of headphones, the difference may be in your hearing — see a professional.
Left Right Audio Test — frequently asked questions
- How do I check if my left and right audio are correct?
- Play a sound to the left channel only and confirm it comes from the left, then do the same for the right. This test does that with short beeps and tells you if the channels are swapped, mono or silent.
- Why are my left and right audio channels reversed?
- Most often the headphones are on backwards or the speaker cables are swapped. Some sound drivers and apps also have a 'swap channels' option. Check the L/R markings first, then your audio software.
- How do I turn off mono audio?
- Windows 11: Settings › Accessibility › Audio › Mono audio. macOS: System Settings › Accessibility › Audio › Play stereo audio as mono. iPhone: Settings › Accessibility › Audio & Visual › Mono Audio. Android: Settings › Accessibility › Audio adjustment (wording varies by phone).
- Why is one earbud quieter than the other?
- Check the balance slider in your sound settings, clean the earbud mesh (earwax blocks sound), and make sure both tips seal equally. If the same earbud stays quieter on other devices, it's likely a hardware fault covered by warranty.
Sources
- StereoPannerNode — MDN Web Docs
Last reviewed .