How to test left and right speakers
- Connect headphones or select your intended speakers in the operating system's audio output menu. Check the Bluetooth connection if you use a wireless headset.
- Start with your device's hardware volume low. The tool has a separate limited-volume slider; actual acoustic loudness still depends on the device and amplifier.
- Press Play left only. You should hear the tone on your left as you face the speakers. It ends automatically after four seconds.
- Press Play right only. It should come from your right. Then press Play both to compare the level and confirm the channels both work.
- Change the frequency to 250 or 1,000 Hz if you want to compare another tone, then press Set test frequency and repeat.
All audio is synthesized inside your browser with the Web Audio API. Nothing is captured with your microphone, and no sound, files or test results are uploaded. Browser audio can only start when you press a button, so this page never autoplays sound.
What a speaker test actually checks
Stereo carries a left and right signal. A sine-wave oscillator generates a predictable tone and a stereo panner routes it to the selected channel. A correctly configured stereo headset should make the left and right buttons easy to distinguish. If the channels sound reversed, inspect headphone labels and speaker wiring; the computer may also have swapped channel routing. If both buttons sound in both ears, check your operating system's mono-audio accessibility setting or any sound enhancements.
This is a listening test, not an electronic measurement. One compact Bluetooth speaker may combine both input channels even when it is working correctly. Phone speakers, soundbars and some USB interfaces can also remap or mix output. For the clearest separation check, try conventional stereo headphones. The test does not identify the physical output device, detect microphone input or record a pass/fail score.
Choosing a test frequency
The default is 440 Hz (the A4 musical note), a familiar midrange sound. Around 250 Hz gives a lower tone; 1,000 Hz gives a higher-midrange signal. This page intentionally limits the frequency range to 125–2,000 Hz and each test to four seconds. A single sine tone cannot measure frequency response or prove that a speaker can reproduce the complete audible range. Small speakers may be much quieter at lower frequencies.
| Frequency | What to listen for |
|---|---|
| 250 Hz | Lower tone, obvious buzzes |
| 440 Hz | Left/right channel identification |
| 1,000 Hz | Higher-midrange channel comparison |
The website's volume slider adjusts the digital test signal, not a measured sound pressure level. The browser cannot know the loudness at your ears, so keep device volume low and stop immediately if the sound feels uncomfortable. This tool is not a hearing test and cannot diagnose hearing loss. Seek a qualified professional for calibrated audio testing or hearing concerns.
What if one side is silent?
- Neither side plays: check tab mute, system volume, output-device selection and Bluetooth pairing. Reload after connecting a new device.
- Only one side works: compare a second pair of headphones on the same device, then try your headphones on another device to narrow down a cable or jack problem.
- Both channels play together: disable mono audio and temporary sound-processing effects, then retry with a stereo headset.
- Crackles or rattles: reduce volume, reseat the connector and check for loose parts. This tool cannot determine the precise physical cause.
Need to check the microphone rather than speakers? Try our mic test. For a continuous audio signal use the white noise generator at a comfortable level; our decibel meter estimates environmental noise but does not certify speaker output.
Frequently asked questions
Can this test tell if my headphones are stereo?
It can help you hear separate left and right channels when your audio settings and hardware preserve stereo. Mono audio or channel mixing may hide the separation even on a working headset.
Why does the left channel play through both speakers?
Your output may be set to mono or mixed by Bluetooth, accessibility settings or a soundbar. Try conventional stereo headphones and inspect audio routing before assuming a fault.
Does this tool access the microphone or upload audio?
No. All test tones are generated on your device; the page does not request microphone access, record sound or upload anything.
Is the test safe for hearing?
The digital signal is limited and automatically stops after four seconds, but actual loudness depends on your equipment. Start with low device volume and stop if uncomfortable.
Last updated: October 17, 2026