Left channel
Expected: the tone comes from your left headphone or speaker; the right channel is silent in the file.
Free stereo channel check
Left right audio test.
Hear where each channel goes.
Check the stereo routing of your headphones or speakers with two short test tones. Play each sample separately: the first contains sound only in its left channel, the second only in its right. No account, microphone or recording upload is needed.
Start with your device volume low and raise it to a comfortable level. Put headphones on the correct ears, or sit between your speakers. Pause one player before starting the other.
Play the left and right test tones
Right channel
Expected: the tone comes from your right headphone or speaker; the left channel is silent in the file.
Each sample is a three-second, 440 Hz stereo WAV. The two files have the same tone and level, with the active channel swapped. Playback starts only when you press play.
Compare what you hear
What should happen?
Left plays left, right plays right: the channels are reaching the expected sides for these samples. This check does not measure sound quality or certify the whole audio system.
The sides are reversed: first check your headphones are oriented correctly. For separate speakers, check their placement and cable connections or the output configuration. Test again after each change.
Both samples play on both sides: mono output, a sound enhancement, adapter, mixer or speaker routing can combine the channels. Speakers can also be heard across a room, so headphones make the comparison clearer.
Only one side plays: check balance and output selection, reconnect the headphones or speakers, and try another device or known-good pair. A single result cannot identify whether the cause is hardware, a cable, a setting or routing.
If the result is unexpected
Check mono audio and balance
For a stereo test, make sure your output supports separate left and right channels, any mono setting is off, and the balance is centered. On iPhone, Apple places Mono Audio and the balance slider under Settings → Accessibility → Audio & Visual. See Apple’s audio settings guide. Restore accessibility settings afterward if you rely on them.
Confirm your browser is using the intended output device, and disconnect adapters or effects one at a time. If both sides work in another application but not this test, check browser and device routing. Very low volume, muted output, wireless connection issues or a single-speaker device can also affect what you hear.
When your own file plays on one side
Check the recording as well as the device
If both test tones reach the correct side but a recording does not, its channel content may differ. Our one-ear audio guide walks through recording and playback checks. Use the free channel splitter to preview the left and right sides of a supported stereo file separately, or compare an averaged mono mix. Keep the original: averaging can make some sounds quieter or cancel them.
Need files for an editor? Explore the WAV audio test files and learn the difference between mono and stereo. Splitting channels keeps all sounds on each side; it does not isolate a voice or instrument from a mix.