Speaker Test — Left, Right, Bass & Headphone Check
Press a button and listen. This speaker test plays the sounds that reveal the usual problems: a dead or swapped left/right channel, a stereo image that is not centered, bass that disappears, a subwoofer that is not doing anything, a speaker wired out of phase. A diagram shows which side should be sounding at every moment, the bass test shows its frequency live as it climbs from 20 to 200 Hz, and the headphone test tells your left ear from your right with a low and a high tone. Every sound is generated in your browser, starts low with a fade, and stops by itself. For a specific frequency or waveform use the custom-frequency tone page instead.
Everything runs in your browser. The test sounds are generated on your device with the Web Audio API. Nothing is uploaded, recorded or downloaded, and the page never asks for microphone access.
How to test your speakers or headphones online
- Turn the volume down first. Set your system volume low and leave the page volume at its default. Raise it slowly while a test plays. Press Stop or Esc at any time to end the sound.
- Run the left and right check. Press "Left channel only", then "Right channel only". The diagram lights the speaker that should be sounding. If the wrong side plays, or both do, the channels are swapped or mixed.
- Check the stereo image and bass. Play "Both channels" and "Left to right pan sweep" (6 seconds) to confirm the sound sits in the middle and glides without jumps. Then run the bass sweep (12 seconds, 20 to 200 Hz) and the subwoofer pulses (40, 60 and 80 Hz).
- Verify phase and headphone orientation. Compare "in phase" with "right inverted": the first should sound solid and centered, the second thin and diffuse. For headphones, the 300 Hz tone must be in your left ear and the 1200 Hz tone in your right.
Use Cases
Frequently Asked Questions
Why does sound come from only one speaker?
First rule out the content: a mono recording plays the same on both sides, and a one-sided file is not a fault. Then check the balance slider in your system sound settings, the "mono audio" accessibility option (it merges both channels), the cable and its plug, and the app volume mixer. Run "Left channel only" and "Right channel only": if one test is silent, the fault is in the speaker, the cable or the output port. If both play on the same side, a balance or mono setting is mixing the channels.
What do crackling, rattling and distortion mean?
Crackling at every volume usually means a loose cable, a dirty jack or a damaged speaker cone. Rattling that appears only at certain notes in the bass sweep is something loose vibrating, such as a grille, a panel or a shelf. Distortion is the speaker overloading: the tone turns fuzzy and worsens as you turn it up. Lower the volume and see which one goes away.
Why can I not hear the bass test on my laptop?
Most laptop, phone and tablet speakers cannot reproduce frequencies below roughly 80 to 100 Hz because the drivers are too small to move enough air. The bass sweep starts at 20 Hz, so expect it to seem silent for the first several seconds. That is a physical limit, not a fault. Headphones, desktop speakers or a subwoofer will play much lower.
Does Bluetooth affect the speaker test?
Bluetooth adds delay, commonly 100 to 250 ms with the default SBC codec and less with AAC, aptX Low Latency or LE Audio. The tests here are not timing-critical, but a Bluetooth speaker that has gone to sleep can swallow the first fraction of a second, so the first beep may be missing. If your headphones also use the microphone, the system may switch them to a low-quality mono hands-free mode, which will make the stereo and phase tests meaningless until it switches back.
Can this test 5.1 or 7.1 surround sound?
No. A web page can only output two channels, so rear, center and subwoofer-channel (LFE) outputs of a surround system cannot be addressed here. Use the system test: in Windows open Sound settings, More sound settings, select your playback device, Configure, then Test each speaker. On macOS open Audio MIDI Setup, select the output device, Configure Speakers, and test each one.
Is this safe for my speakers and ears?
The page caps its own output, every sound fades in and out over at least 30 milliseconds to avoid pops, each test ends by itself and the Stop button and Esc key cut the sound within a fraction of a second. Your system volume still decides how loud it really is, so start low. Low bass and steady tones can be harder on speakers and ears than music at the same setting.
What each speaker test plays and what you should hear
The reference below is generated from the same list the buttons use, so the lengths and descriptions match what the page plays.
| Test | Length | What plays | What you should hear |
|---|---|---|---|
| Left channel only | 3.7 s | 5 short beeps on the left channel only | Left speaker only |
| Right channel only | 3.7 s | 5 short beeps on the right channel only | Right speaker only |
| Both channels (center) | 3.7 s | The same beeps on both channels | Centered between the speakers |
| Left to right pan sweep | 6 s | A steady tone glides from the far left to the far right over 6 seconds | Smooth left-to-right movement |
| Bass sweep 20-200 Hz | 12 s | A sine tone sweeps from 20 Hz to 200 Hz in 12 seconds, equal time per octave, with the current frequency shown live | Rising tone, both speakers |
| Subwoofer pulses | 4 s | Three one-second sine bursts at 40, 60 and 80 Hz | Low thumps, both speakers |
| Phase test: in phase | 6 s | Pink noise sent identically to both channels | Solid, centered image |
| Phase test: right inverted | 6 s | The same noise with the right channel polarity flipped (gain of -1) | Thin, diffuse, weak bass |
| Voice-band noise bursts L/R | 5.1 s | Band-limited pink-noise bursts (roughly the range of a speaking voice): left, right, left, right, then both together | Left, right, left, right, both |
| Headphone left/right check | 5.9 s | A low tone (300 Hz) is always the left ear and a high tone (1200 Hz) is always the right ear, three times | Low = left ear, high = right ear |
- This is a listening test, not a measurement. Browser output goes through your operating system mixer and any enhancements, so it shows whether something works and sounds right, not how flat the response is.
- The page only sends two channels. Testing rear or center speakers of a 5.1 or 7.1 system needs the operating system test.
Related tools
More free, in-browser tools from the Device Tests set — every one runs locally, with no sign-up and no upload.