About Microphone Test and How It Measures

Who makes this

Microphone Test is built and run by 1000 Ventures, a small studio that makes free, single-purpose web tools. We built it because the usual way to test a mic is to join a call and ask "can you hear me?", which is slow and a little awkward. The site is written by our team. No expert has reviewed it, and we do not claim otherwise.

How the microphone test works

The microphone test uses standard browser features and nothing else. There is no plugin, no app and no server step.

1. Access. The page asks for the microphone through getUserMedia, the browser function every video call site uses. You decide whether to allow it.
2. Measurement. A Web Audio AnalyserNode hands the page the raw audio samples, 2,048 at a time. From each block we compute the RMS level and the highest sample, both in dBFS.
3. Verdict. Over a rolling ten-second window, the test compares your loudest moments with the quiet moments in between (the 10th percentile, which we call background). It also counts how often the signal touches full scale. From that it decides: working, very quiet, no sound, too loud or noisy.
4. Recording. When you press Record, the browser's MediaRecorder captures a clip into memory. It plays back from there and disappears when you close the tab.

The thresholds we use

Verdict	Rule
No sound	Every sample is zero, or the level never rises above -90 dB
Too loud	More than 2% of blocks reach 99% of full scale
Very quiet	The loudest block stays below -50 dB, or rises less than 10 dB above the background, after five seconds
Noisy	Background above -50 dB and the voice less than 12 dB above it
Working	None of the above

We picked these numbers from common recording practice for speech. They are a practical guide, not a standard, and we will tune them as we learn. If you think the test misreads your mic, tell us.

Accuracy and limits

• dBFS is not loudness in the room. It says how full the digital signal is. The same voice can read 10 dB apart on two mics or at two input volume settings.
• Browsers do not always obey. We ask the browser to switch off echo cancellation, noise suppression and automatic gain. Some browsers and phones keep some processing on anyway. Mic details in the tool shows what your browser reports.
• Phones. On many phones the system picks the mic for you, and the list shows only one entry.
• It does not test your speakers. If you cannot hear the playback, check your output device and volume.

Built on open standards

• W3C: Media Capture and Streams (getUserMedia)
• W3C: Web Audio API (AnalyserNode)
• W3C: MediaStream Recording (MediaRecorder)
• MDN Web Docs: MediaDevices.getUserMedia()

How this is funded

The site is free and currently shows no ads. If we add ads later, they will never sit inside the tool or change what it tells you, and we will update the privacy page first.

Contact

Questions, bugs or corrections: michael@1000ventures.io. More on the contact page.