Microphone Tester

The Microphone Tester is a quick way to check whether your computer or phone's microphone is recognized by the browser and is actually picking up sound. Once you start it and speak, a live volume bar moves with your voice, and a text message tells you when sound is coming in. It answers that one question only. It cannot record and play back (so you cannot hear how you sound), it cannot choose which microphone to use, it does not measure exact decibels, and it does not check for echo or background noise.

How to use it

1. Click 'Start Microphone Test'. Your browser asks for permission; allow microphone access. The button then changes to 'Stop Test'.
2. A 'Live Volume' bar appears. Speak or clap near the microphone and watch whether the bar responds.
3. When the level passes a small threshold the bar takes the accent color and the text reads 'Sound detected, your microphone is working fine'. With no sound it says 'Try speaking or making a sound into the microphone'.
4. When you are done, click 'Stop Test'. The microphone is released and the bar disappears. It is also released automatically when you leave the page.

How the volume bar is calculated

The code uses the browser's audio analysis interface. Each frame it reads the strength of 128 frequency bands (each value from 0 to 255), averages them, divides by 128, multiplies by 100, and caps the result at 100. That is the bar's percentage. When the percentage is above 5, the tool decides sound has been detected. Since it is an average of band strengths rather than a calibrated decibel reading, the number is only useful for 'is there signal, and roughly how strong', and values are not comparable between devices. A usage scenario: before a video meeting you want to be sure the headset microphone is not muted. Click start and say a normal sentence. If the bar clearly rises and falls, both the system and the browser are receiving sound from that microphone.

Supported input and known limits

• It uses the system's current default microphone. There is no device drop-down on the page. If several microphones are connected, change the default in your operating system's sound settings first.
• Browsers only allow microphone access on a secure connection (HTTPS or localhost) and only after you approve it. If you denied it earlier, re-allow it in the site settings next to the address bar.
• When access fails you see 'Could not access the microphone. Please make sure you've granted the browser microphone permission and that your device is properly connected.' The message does not distinguish between a denied permission, a missing device, or a device in use elsewhere.
• The code requests audio with the browser's default settings and turns nothing off. Many browsers enable echo cancellation, noise suppression, or automatic gain by default, so the bar may reflect processed sound rather than the raw microphone input.
• The 'sound detected' threshold is a fixed 5%. In a very quiet room it may occasionally not register, and in a noisy room it may show sound constantly. Neither says anything about microphone quality.
• There is no recording or playback, so you cannot judge sound quality or spot hum.
• If another program has exclusive use of the microphone, the browser may get no sound.

FAQ: I clicked start but no permission prompt appeared. What now?

Look for a blocked-microphone icon near the address bar. If the site was previously set to 'Block', change it to allow in the browser's site settings and reload. Also make sure the page was opened over HTTPS.

FAQ: The bar never moves. Is my microphone broken?

Not necessarily. Common causes: the wrong default input device selected, a headset with a hardware mute switch, the operating system blocking microphone access for the browser, or a meeting app holding the microphone. Check whether the input level in your system sound settings reacts, then test again.

FAQ: Is a high bar a good sign?

The bar only shows how strong the incoming sound is, not how good it is. Sitting too close or using too much gain can drive it high while the sound distorts. The tool does not judge quality; it just confirms there is a signal.

FAQ: Does it secretly record me?

No. The code only reads analysis data in real time to draw the bar. It has no logic to save or send sound. See the section below for details.

Privacy and processing

Sound is analyzed live inside your browser only. The code reads strength data from the browser's audio analysis interface to update the bar; it creates no recording, saves no audio, and makes no request that sends sound to a server. When you click 'Stop Test' or leave the page, the code stops every microphone track and closes the audio context, so the browser's microphone-in-use indicator should go away.