Why does the left/right test use noise instead of a musical tone?

A short burst of noise covers the full frequency range at once, so it reveals a dead tweeter, a buzzing driver, or a channel that's simply silent more reliably than a single pitch would.

Is the frequency I stopped the sweep at my exact hearing limit?

It's a reasonable estimate, not a medical measurement. Your result depends on your speakers or headphones actually being able to reproduce that frequency accurately, on ambient noise in the room, and on volume level — cheap earbuds and older devices often can't reproduce anything much above 15-16kHz regardless of your hearing.

My speakers sound the same whether the phase test is in-phase or out-of-phase — is something wrong?

Not necessarily. The difference is easiest to hear on stereo speakers placed a few feet apart, sitting roughly equidistant from both; it's much subtler on headphones or a single mono speaker, and a room with heavy echo can mask it too.

Yes. Every tool is free to use, with no account and no credit card. The work runs on your device rather than on our servers, which is what keeps it free to run.

Does it work on mobile?

Yes. It runs in current mobile browsers on iOS and Android, with nothing to install.

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Free Speaker Test

Test left/right stereo channels, sweep the full 20Hz-20kHz frequency range to check your hearing range, and run a stereo phase test — all synthesized live in your browser, no audio files.

Runs in your browserNo sign-up, no pop-upsNo login requiredFree foreverNo audio filesLeft/right/phase test20Hz-20kHz sweep

Works offline once loaded

Turn your volume down before you start

This tool plays tones and noise bursts, including very low and very high frequencies. Lower your speaker or headphone volume first, and take headphones off if they're loud — you can turn it back up once you know the level is comfortable.

How It Works

Run three independent speaker checks, all generated live in your browser — no audio files involved.

1
Turn your volume down
Acknowledge the volume warning first. This also grants the page permission to play audio, which browsers require to come from a real tap or click.
2
Check left, right and both channels
Tap each button to hear a one-second noise burst panned to that channel, and confirm the matching speaker is the one making sound.
3
Sweep the frequency range
Drag the slider to any pitch from 20Hz to 20kHz, or start the auto-sweep and tap "Stop — that's my limit" the moment you stop hearing it, to estimate the top of your hearing range.
4
Run the phase test
Play the same tone in-phase and out-of-phase and listen for the difference — in-phase sounds centered, out-of-phase sounds diffuse and hard to localize.

Nothing is recorded or uploaded. Every tone and noise burst is synthesized on the fly with the Web Audio API and exists only for the moment it plays.

Guide

Worked example

Turn the volume on your device down, open the page and press "Ready to test" under "Turn your volume down before you start". In "Left / right channel test", press "Left": a one-second burst of white noise plays from the left speaker only and the "Left" button turns teal. Press "Right", then "Both". Next, in "Frequency sweep (20Hz-20kHz)", press "Auto-sweep from 20Hz upward". A sine tone climbs from 20 Hz, the big readout rises, and the slider and "Play tone" lock. The sweep takes about 15 seconds to reach 20.0 kHz. Press "Stop — that's my limit" when the tone vanishes. At 12.6 kHz the page says "You stopped the sweep at 12.6 kHz — that's roughly the top of your hearing range right now."

Which settings to use, and the limits

Turn the volume down before the first test. Nothing plays until you press "Ready to test" on the volume warning, and that press also starts the audio engine. The tool has no volume control of its own: the noise burst is played at half of full scale and the tones at 30 percent, so your device volume sets the loudness. The tests include very low and very high frequencies, so start quiet and raise the volume once you know the level is comfortable.
Check left and right one at a time. "Left", "Both" and "Right" each play a one-second burst of white noise with a 40 millisecond fade in and out, panned fully left, to the centre, or fully right. The page describes this as a check that each speaker works and is wired to the correct side. If "Left" plays on your right, or one side stays silent, check the cables and your system's sound settings. Pressing another button stops the current sound first.
Use the slider for a fixed tone. The slider covers 20 Hz to 20 kHz on a logarithmic scale, so equal movements sound like equal changes in pitch, and it starts at 1000 Hz, shown as "1.00 kHz". The readout shows whole Hz below 1 kHz, two decimals up to 10 kHz and one decimal above. Press "Play tone" for a steady sine tone; if you move the slider while it plays, the pitch follows at once. The tone stops when you press "Stop tone".
Run the auto-sweep to find your upper limit. The sweep climbs from 20 Hz in 250 steps, one every 60 milliseconds, which is about 15 seconds to reach 20 kHz. While it runs the slider and "Play tone" are disabled. Press "Stop — that's my limit" the moment you stop hearing it. The number shown is the frequency on screen when you pressed. It depends on your volume and your speakers or headphones, and the tool does not calibrate or measure anything. If you let it run out, nothing is recorded.
Use the phase test to spot a reversed speaker. "Play phase test" sends a 220 Hz tone to both channels. With the switch on "In-phase" the sound should seem to come from a single point between the speakers. Flip it to "Out-of-phase" and the right channel is inverted, which should sound hollow and hard to place. You can flip the switch while the tone plays and the change is immediate. The page calls a hollow, diffuse sound in the in-phase position a classic sign of a miswired speaker or cable.

Common problems and how to fix them

It says "Your browser doesn't support the Web Audio API, so this tool can't generate test sounds here. Try the latest version of Chrome, Edge, Firefox or Safari.": The page found no audio engine in the browser, or creating one failed when you pressed a button. Every sound here is generated live, so without it nothing can play. Update the browser or try another one.
It says "Something went wrong playing that sound. Try again, or reload the page if it keeps happening.": This appears when building the sound fails in the channel test, the tone, the sweep or the phase test. The red box does not clear itself, so if sound works again on a second try the old message may remain; reloading the page removes it. If it comes straight back, try another browser.
The sound stopped when you switched tabs.: When the tab is hidden the tool stops every sound and suspends the audio engine. On return it resumes the engine but leaves the sound stopped, so nothing restarts by itself. Press the button again.
The slider and "Play tone" are greyed out.: The auto-sweep is running, and it disables both. Wait until it reaches 20 kHz, which takes about 15 seconds, or press "Stop — that's my limit". They work again straight afterwards.
On an iPhone the buttons work but you hear nothing.: Safari treats web audio as ambient by default, so the ring/silent switch can mute it. On Safari 16.4 and later the tool declares the page's audio as playback each time you press a button, so the switch should not matter. On older versions, switch off silent mode and check the volume.

How it compares

The Speaker Test plays stereo test signals through whatever your device is set to output to: white noise on the left, right or both, a sine tone from 20 Hz to 20 kHz, and a 220 Hz phase tone. It is a quick listening check of wiring, balance, phase and the top of your hearing. It uses no microphone, so it cannot measure frequency response, loudness or distortion, and it has no surround-sound channel test, only stereo. A measurement microphone with analysis software, or a test disc, is what you need for numbers. Everything is generated in your browser and nothing is uploaded.