Mic Test

Why the playback matters more than the meter

Most microphone testers show you a bar that wiggles. That answers exactly one question — is any signal arriving — and it is rarely the question people actually have. Hum from a laptop charger, echo from speakers, a muffled built-in microphone, a fan in the background, a headset picking up your breathing: none of that shows on a meter. All of it is obvious the second you hear the recording.

That is why this tool records six seconds and plays them back. It is the same reason sound engineers listen before they trust a level: you cannot see a problem you can only hear.

The live view is not decoration either. The meter is calibrated in decibels rather than being an arbitrary bar, so "too quiet" and "clipping" are measurements rather than guesses, and a peak marker holds the loudest moment for a beat so you can catch spikes the eye would otherwise miss.

Reading the meter

Decibels here are dBFS — decibels relative to the loudest value the system can represent, so 0 is the ceiling and everything else is negative. The scale is logarithmic, which is why the meter is drawn linear in decibels rather than in raw amplitude: an amplitude bar spends nearly all its travel in the top few decibels and looks broken at normal speaking volume.

Fixing a microphone that will not work

The meter does not move at all

Check the physical mute first. Most headsets have an inline mute switch or a mute button on the earcup, and many laptops have a mute key with its own indicator light — these override everything in software and nothing on screen will tell you they are engaged. Then check the device list here: laptops very often stay on the built-in microphone even after a headset is plugged in.

"The device is busy"

Another application is holding the microphone. Zoom, Teams, Meet, Discord, OBS and voice recorders all keep it open in the background, and minimising the window does not release it. Quit them properly and try again.

"Permission was refused"

Click the microphone or lock icon in the address bar, set microphone access to Allow, and reload. In Chrome and Edge the full list is under Settings → Privacy and security → Site settings → Microphone. On Windows, also check Settings → Privacy & security → Microphone; on a Mac, System Settings → Privacy & Security → Microphone.

It works here but not in one specific app

Then the microphone is fine and that app has its own input selected. Every call application keeps a device setting separate from the system default, and they routinely disagree. Open the audio settings inside that app and pick the same device you selected here.

There is a hum or buzz in the recording

A steady low hum is almost always electrical — an unearthed laptop charger is the usual culprit. Unplug the charger and record again. If the hum vanishes, try a different socket or a different charger, or move the microphone cable away from power cables.

You hear an echo of your own voice

Your speakers are being picked up by the microphone. Headphones fix it completely. The readouts show whether the browser's echo cancellation is on, which helps but cannot fully remove a loud speaker sitting next to an open microphone.

The three processing flags

Browsers apply audio processing before you ever hear the signal, and this tool reports whether each piece is active because it changes what you are measuring.

• Echo cancellation subtracts your speakers' output from the microphone feed, so the far side does not hear themselves. It also slightly dulls your voice.
• Noise suppression removes steady background sound such as a fan or air conditioning. It can make a quiet voice sound thin, because it cannot always tell you apart from the noise.
• Auto gain control raises and lowers the level for you. It is why the meter sometimes settles into a comfortable range on its own — and why a genuinely quiet microphone can look fine on a meter while sounding noisy in playback, since the noise gets amplified along with your voice.

All three make calls better and measurements less literal. If a reading says "Not reported", the browser simply did not expose it — Firefox and Safari are less forthcoming here than Chrome, and that is not a fault.

Privacy — what happens to the audio

The microphone feeds an analyser inside this page. Nothing is transmitted, and there is no server involved in the test at any point.

• The live signal is never stored. It is measured frame by frame to draw the meter and waveform, and then discarded.
• The recording lives in this tab only. It is held in memory, replaced when you record again, and gone when you close the page.
• Downloading is the only way it becomes a file, and that save goes straight to your own downloads folder.
• The microphone is released when you leave. Closing the tab or pressing Stop ends the track and the recording indicator goes out.

Your browser's own recording indicator is the ground truth, not any promise this page makes. Our full privacy policy covers the rest of the site.