Speaker & Headphone Test Online: Left/Right, Bass, Sweep

How to use it

Turn the system volume down and connect your headphones or speakers.

On the Left & Right tab, tap Left and Right and say where you heard the sound.

On Frequencies, start the sweep and mark when the tone appears and disappears.

On Bass & Phase, check bass, cabinet rattle and speaker polarity.

Tap “Stop all sounds” or press Esc at any time.

Features

Separate left, right and center test with a voice-like sound or pink noise

Blind check (random side) to confirm swapped channels for sure

Logarithmic 20 Hz–20 kHz sweep with a live frequency readout

Single tones at 50, 100 and 440 Hz and 1, 10 and 15 kHz

Bass test, rattle/buzz check and speaker phase (polarity) test

Left/right signal meters that separate software problems from hardware faults

Output device selection in browsers that support it

No audio files, no recording; works on iPhone and Android

What this tool tests#

Every sound is generated right in your browser with Web Audio. No audio file is downloaded and nothing is recorded. The tool has four parts:

Left and right: the sound goes to one channel only. The blind check picks a random side so your answer isn't a guess.
Frequency sweep: a soft tone rises from 20 Hz to 20 kHz while the current frequency is shown.
Single tones and bass: for comparing two speakers and finding distortion or crackle.
Phase: shows whether both speakers are wired the same way.

How to read the results#

If the “left” sound came from the right, the channels are swapped. Check how you're wearing the headphones (L and R marks) first, then the speaker wires.
If both sides sounded like they came from the middle, Mono audio is on or the device has a single speaker.
In the sweep, where you start hearing depends mostly on the speaker; where you stop hearing depends mostly on your ears. Phone and laptop speakers usually play almost nothing below 150 Hz.
The L and R bars at the top show which channel the signal actually went to. If the bar moves but you hear nothing, the problem is after the browser: sound settings, driver, cable or the speaker itself.

Hearing range by age#

Healthy ears hear roughly 20 Hz to 20 kHz at best, but the upper limit drops with age:

Under 25: usually 17 kHz or higher
Up to about 40: around 15–16 kHz
40 to 55: around 12–14 kHz
Over 60: often below 10 kHz

This is not a medical device. If your two ears differ a lot or you hear ringing, see an audiologist.

Why is one side silent?#

Balance: on Windows open Sound settings and the device's Properties; on Android look under Accessibility; on iPhone go to Settings > Accessibility > Audio & Visual. Set the Balance slider to the middle.
Mono audio: with Mono audio on, both sides play the same sound, so the left/right test seems to come from the center.
Cable and plug: a 3.5 mm plug that isn't fully inserted often cuts one side. Rotate the plug slowly; if the sound cuts in and out, the cable or jack is faulty.
Bluetooth: with earbuds, sometimes only one connects. Put both in the case, forget the device in Bluetooth settings and pair again.

Bluetooth headphones and codecs#

Bluetooth sound quality depends on the codec. SBC is the basic one, AAC works well on iPhone, and aptX and LDAC offer higher quality on some Android phones. With a weak codec, or when the headset microphone is active and the headphones switch to call mode, high frequencies roll off earlier — so a low limit in the sweep doesn't always mean weak hearing. A little Bluetooth delay is normal too.

Tips#

Start quiet and raise the volume slowly; loud high tones can damage hearing.
Keep the volume fixed when comparing two headphones.
A medium volume is enough for the rattle check; some cabinet buzz at very high volume is normal.

Frequently asked questions

Why can't I tell left from right on my phone?

Most phones have one speaker or two speakers very close together, so stereo effectively comes from one spot. Do the left/right test with headphones; if the phone has two speakers, hold it sideways.

My highest audible frequency is low — is something wrong with my ears?

Not necessarily. Laptop speakers, cheap headphones and Bluetooth codecs also lower the limit. Repeat with good wired headphones; if it's still under 10 kHz and you're young, get a hearing test.

Why is there no sound at all on my iPhone?

On some iOS versions the ring/silent switch also mutes web pages. Turn silent mode off, raise the volume with the side buttons and tap the test button again.

Can this test damage my speakers or ears?

Not at low or medium volume. But don't play bass or very high tones at full volume for long — it can harm your hearing and burn out a small speaker or tweeter.