Which test to use
The audio tests play sound that the browser generates on the spot and send it to whatever output your system has selected. Nothing is recorded, and no microphone permission is asked.
The speaker test is for built-in laptop speakers, desktop speakers, soundbars and speakers on a monitor. It plays a 440 Hz tone on the left, the right or both channels, a sweep from 20 Hz to 20 kHz, and a separate bass sweep. It is the fastest way to find a dead or swapped channel and to hear where your speakers stop producing bass.
The headphone test is for wired and Bluetooth headphones and earbuds. Besides the tone in each ear and the full sweep, it has a phase check: the same tone plays in both ears and the right ear is inverted every two seconds. On healthy headphones you hear the tone jump between a narrow spot in the middle of your head and a hollow, diffuse sound; if the tone goes wide in the in-phase state and centred in the inverted one, one driver is wired backwards. It also shows the output latency the browser reports, a useful hint when video and sound drift apart on Bluetooth.
The tone generator gives you full control: any frequency from 20 Hz to 20 kHz, four waveforms (sine, square, triangle and sawtooth) and left, centre or right. It names the nearest musical note, so it also works as a reference pitch, a way to find a rattling frequency in a room or car, or a simple signal for testing an amplifier.
How to get a reliable result
Turn the volume down before the first press of Play, then raise it until the tone is clear. Switch off spatial audio, equalisers, bass boost and loudness settings in the operating system and in any headphone app, because they change what you hear. Check that the balance is centred and that the right output device is selected, especially on a laptop connected to a monitor with speakers. Test in a quiet room.
When the fault is the hardware
Once the settings are ruled out, swap things around. Move the cable to the other side, try the headphones on another device, or play the same test through a different pair. If the fault follows the speaker or the headphones, they are defective; if it stays with the computer, look at the sound card, the port or the driver. A new pair with a dead channel or a constant buzz should go back within the return window.
Frequently asked questions
Should I use the speaker test or the headphone test?
Use the one that matches what is plugged in. Both play left, right and sweep checks, but the headphone test adds a phase check that reveals a driver wired backwards and shows the output latency, which matters for Bluetooth. The speaker test adds a bass sweep that finds the low limit of small speakers and rattles in the cabinet.
Why is there no sound when I press Play?
Browsers only start audio after a click or tap, so press Play again if nothing happened. Then check the output device in the system sound settings, the volume of the browser tab, and the silent switch on an iPhone or iPad. If headphones are connected over Bluetooth, the sound goes to them, not to the built-in speakers.
Is it safe to play high tones through headphones?
Yes, at a sensible volume. Start with the volume low and raise it slowly, especially with the tone generator and the sweep, because a pure tone sounds louder than music at the same setting. Never press your ear to a speaker playing a high tone, and stop if you feel discomfort or ringing.
Can these tests tell me how good my speakers sound?
They tell you whether each channel works, whether the sides are the right way round, where the bass stops and whether something rattles or buzzes. They do not rate sound quality, because the page generates the signal and has no microphone to hear what comes out. For measured frequency response you need a calibrated microphone.